First, it's not that common with TGP (thumbnail gallery posts) to have the 'enter/exit' pages... look at our trading partners, their trading partners and the partners of their trading partners...
Second, I've tried those enter pages and the most of our trades resigned... and the remaining surfers didn't click enter / exit but... closed the window. They thought they were going to a paysite, those have enter/exit pages.
What I'm going to do to to keep the minors out, is keeping keywords that most childblocker programs will recognize and edit 'adult ratings' metatags to keep it 'explicit material'. Perhaps I'll also add that black black box at the top of the page we used to have: 'Warning - this page contains adult material' etc.
http://web.archive.org/web/20030608085548/http://www.peachy18.com/