As far as I know people are still using ultrasonics, but I believe it's the heat rather than the sonics that are doing the steeping. There was a post by a scientist who had knowledge of ultrasonics a while back that said unless the machine is specifically tuned for working with the viscosities of eliquid the sonics won't do much - so a device designed to clean jewelry won't have much effect at all.
Ah, rats. Thanks for answering!