People have used a lot of techniques, depending on the specific body-part involved and their particular skills, from trans-mapping body-parts to using the Tailor program or editing out the poke-thru with post-work. In your case I think if you invested some time learning the use of magnets in Poser, you'd get results you'd be happy with in pretty short order. Besides your Poser 5 Handbook, you can find tutorials via the link atop this page, and a lot of tips you'd likely find helpful via the Poser Forum Backroom Resources link in the masthead above as well.