Note 79 — Chapter XVI · THE FRAGMENTS OF THE LOST TRAGIC POETS.
Reading edition
It is clear that γὰρ ὤθουν is wrong. The best suggestion seems to be γ' ἄνωθεν, adopting which we may render the lines thus:
Naked above, their radiant arms displaying, In lustihood of ruffling youth, and bloom Of beauty bright on stalwart breasts, they fare; Their shoulders and their feet in floods of oil Are bathed, like men whose homes abound in plenty.