Mainstream backlinks to porn sites

I already posted in the mainstream board and got some good responses but I would like some more feedback to give more color to the picture.

I subscribe to a mainstream backlink list service, so each month I get a list of pr4-7 backlinks from mainstream blogs that allow me to create profiles or profile comments with targeted anchor text links.

I have found a fetish non nude porn niche that for some longtail keywords should not be too hard to rank for with these backlinks.

Basically I'm wondering if there are any penalties by Google for using mainstream backlinks for the purpose of improving my website's porn serps. Normally i would not consider doing this but it is a non nude, non sex act fetish niche.

Thanks in advance for your responses.