Here's the link to the current dmoz guidelines for adult sites.
http://dmoz.org/guidelines/adult/adultguidelines.html
It's kind of fucked up: to reach the dmoz adult section, you have to type in the url: www.dmoz.org/adult--there's no link to it on the dmoz.org main menu.
I don't know how much help it is for gallery sites to be on dmoz. My site is adult humor, and it's great--I've gotten a number of unsolicited links to my site from my dmoz listing. (They show up in my google listings.) Granted, they're from directories I've never heard of, but still...
And I do get surfers too, mostly the "bored at work" crowd who'll work there way through section of the directory--I've done so myself.