Heh, I wish I had a fetish. It'd make a great opener!
*struts up to a HB10 with a smile on his face*
Smurf: "Hi"
HB10: "Hi"
Smurf: "I have a fetish for feet"

ok maybe not. But still, I'd throw it in to a conversation, especially if *sex* (as a topic) had come up previously. Today I mentioned to a girl that I'd had a sexual experience with another guy before. She smiled and said she admired how confident I was about admitting that. I was like "SCORE!" (in my head). Which was weird, cause I actually danced around the point a lot and was quite embarrassed admitting it, all I did was lean back, cross my arms, and give a confident smile while I stuttered. Worked like a charm.
I live by the "What you say is only 7% of the game" rule. So talking about a fetish is fine if you got the body language to back it up.