I've had the tickling fetish request, plus I've had someone who mentioned tickling who I saw a few years ago phone back and start asking about it.
Now I don't mind answering enquiries re such things when it's "Hi Strawberry I'd really like to come see you and have a fetish for tickling, I'll explain when we meet I'm sure you'll be ok with it what do you think?" I'll respond something along the lines of "Sure could you just elucidate a little", "Yep would you mind if I suck your toes and tease you a little?", "No not at all". So we meet and he expands tells me more specifics and we have some fun.
What turns me off are the enquiries that are made in a long-winded, whiney voice, usually for some reason tends to be a southern accent that go on and on and want to ask exactly how ticklish are you, in much the same way guys who phone for a chat about their fantasy do.
Result is as soon as I hear tickling, or wrestling (another one) I turn right off. I have however met plenty of guys who have certain fetishes, they tend to make a quite check, turn up and do it rather than spend ages talking about it.