And the citation in Clement might well go back to a Platonic reframing of Heraclitus's statement - Pigs wash themselves in mud, birds in dust or ash. (fr. 37). Plato interestingly writes "the eye of the soul is sunk in barbarian mud"
(a) Plato, Resp. 533d ἡ διαλεκτικὴ µέθοδος… τῷ ὄντι ἐν βορβόρῳ βαρβαρικῷ τινι τὸ τῆς ψυχῆς ὄµµα κατορωρυγµένον ἠρέµα ἕλκει καὶ ἀνάγει ἄνω…
(b) Plotin. Enn. 1.6.5 Ἔστι γὰρ δή, ὡς ὁ παλαιὸς λόγος, καὶ ἡ σωφροσύνη καὶ ἡ ἀνδρεία καὶ πᾶσα ἀρετὴ κάθαρσις καὶ ἡ φρόνησις αὐτή. Διὸ καὶ αἱ τελεταὶ ὀρθῶς αἰνίττονται τὸν µὴ κεκαθαρµένον καὶ εἰς Ἅιδου κείσεσθαι ἐν βορβόρῳ, ὅτι τὸ µὴ καθαρὸν βορβόρῳ διὰ κάκην φίλον· οἷα δὴ καὶ ὕες, οὐ καθαραὶ τὸ σῶµα, χαίρουσι τῷ τοιούτῳ. Τί γὰρ ἂν καὶ εἴη σωφροσύνη ἀληθὴς ἢ τὸ µὴ προσοµιλεῖν ἡδοναῖς τοῦ σώµατος κτλ.
‘
(c) Clemens Alexandrinus, Stromata II, 20, 118, 5 οἳ δὲ εἰς ἡδονὴν τράγων δίκην ἐκχυθέντες, οἷον ἐφυβρίζοντες τῷ σώµατι, καθηδυπαθοῦσιν, οὐκ εἰδότες ὅτι τὸ µὲν ῥακοῦται φύσει ῥευστὸν ὄν, ἡ ψυχὴ δὲ αὐτῶν ἐν βορβόρῳ κακίας κατορώρυκται, δόγµα ἡδονῆς αὐτῆς, οὐχὶ δὲ ἀνδρὸς
ἀποστολικοῦ µεταδιωκόντων.
Notice the 'coincidence' that at the core of the Clement reference is the Platonic play on words borboros/barbaros viz. βορβόρῳ βαρβαρικῷ . I think we have discovered something important.
Let's cite Plato's original criticism of those who follow Orphic myths:
“You will not be able, dear Glaucon, to follow me further,1 though on my part there will be no lack of goodwill.2 And, if I could, I would show you, no longer an image and symbol of my meaning, but the very truth, as it appears to me—though whether rightly or not I may not properly affirm.3 But that something like this is what we have to see, I must affirm.4 Is not that so?” “Surely.” “And may we not also declare that nothing less than the power of dialectics could reveal5 this, and that only to one experienced6 in the studies we have described, and that the thing is in no other wise possible?” “That, too,” he said, “we may properly affirm.” “This, at any rate,” said I, “no one will maintain in dispute against us7: that there is any other way of inquiry1 that attempts systematically and in all cases to determine what each thing really is. But all the other arts have for their object the opinions and desires of men or are wholly concerned with generation and composition or with the service and tendance of the things that grow and are put together, while the remnant which we said2 did in some sort lay hold on reality—geometry and the studies that accompany it— are, as we see, dreaming1 about being, but the clear waking vision2 of it is impossible for them as long as they leave the assumptions which they employ undisturbed and cannot give any account3 of them. For where the starting-point is something that the reasoner does not know, and the conclusion and all that intervenes is a tissue of things not really known,4 what possibility is there that assent5 in such cases can ever be converted into true knowledge or science?” “None,” said he.
“Then,” said I, “is not dialectics the only process of inquiry that advances in this manner, doing away with hypotheses, up to the first principle itself in order to find confirmation there? And it is literally true that when the eye of the soul6 is sunk in the barbaric slough (βορβόρῳ βαρβαρικῷ) of the Orphic myth, dialectic gently draws it forth and leads it up, employing as helpers and co-operators in this conversion the studies and sciences which we enumerated, which we called sciences often from habit,2 though they really need some other designation, connoting more clearness than opinion and more obscurity than science. ‘Understanding,’3 I believe, was the term we employed. But I presume we shall not dispute about the name ...
The context of this statement in the Republic is to juxtapose superstition with logic and reason:
As the capstone of the sciences, dialectic is set over them (Republic 534). When
presenting the analogy of line, Plato had Socrates comment that in the higher subsection
of the world of reality/intellect, “the soul passes out of hypotheses, and goes up to a
principle which is above hypotheses, making no use of images as in the former case, but
proceeding only in and through the ideas themselves” (Republic 510-511). Now, Plato
reveals that this process is what science, namely dialectic, is all about. As Socrates puts
it:
Then dialectic, and dialectic alone, goes directly to the first principle and is the
only science which does away with hypotheses in order to make her ground
secure; the eye of the soul, which is literally buried in an outlandish slough, is
by her gentle aid lifted upwards; and she uses as handmaids and helpers in the
work of conversion, the sciences which we have been discussing. Custom terms
them sciences, but they ought to have some other name, implying greater
clearness than opinion and less clearness than science: and this, in our previous
sketch, was called understanding. (Republic 533)
Thus, through dialectic the soul finally reaches the idea of good. In this final ascent, the
soul does not employ the assistance of the senses at all; it uses only the Forms in its
reasoning, and at last it arrives at the end of the intellectual world, specifically at the
idea of good. Once the soul reaches this first principle, it can retrace its path back to
where it started, which is the hypothesis of other sciences. This whole process of
discovering the truth is best illustrated by the “Allegory of the Cave.”
So when Clement writes this:
Such also are those (who say that they follow Nicolaus, quoting an adage of the man, which they pervert, "that the flesh must be abused." But the worthy man showed that it was necessary to check pleasures and lusts, and by such training to waste away the impulses and propensities of the flesh. But they, abandoning themselves to pleasure like goats, as if insulting the body, lead a life of self-indulgence; not knowing that the body is wasted, being by nature subject to dissolution; while their soul is buffed in the mire of vice ( ἡ ψυχὴ δὲ αὐτῶν ἐν βορβόρῳ κακίας κατορώρυκται); following as they do the teaching of pleasure itself, not of the apostolic man (οὐχὶ δὲ ἀνδρὸς ἀποστολικοῦ μεταδιωκόντων).
His point is that Clement is comparing the followers of Nicolaus to the Orphics (whose mythologizing was juxtaposed against 'true science' by Plato). It would seem that he has already changed the sense of borboros to mean something sexual which wasn't in the Platonic original. Perhaps he knew that they engaged in myth-making. But this seems to have been inferred only from Epiphanius.