Hmm... on some trade scripts (like Adult Monger ), you can add a line of code to each link to send out.
So, let's say you had 10 interracial sites you trade with, and you had ten links to interracial galleries. You would put this snippet of code on the end of each link set with a chance to send out to these 10 trades.
When you sign up for another TGP's trade; instead of putting
www.tgp.com as your linkback,
you would put in
www.tgp.com/interracial.html
Make sense?
I know it seems like a lot of work, but it would be worth it for the extremely productive traffic.
There probably is an easier way out there, but this is the only one I could think of...