One time I made a Tinder and HotOrNot account with my female pictures on it, not to attract men but to see if guys could figure out from my pics I was a guy.
Only a very few were able to figure out I was a man. Pretty much everyone else had no idea and would match me and try to go for a hookup. I would tell them I was a man and it would scare most of them off, but there were a few who didn't care and would just be even more aggressive trying to get that hookup. At that point I would just block them.
I eventually stopped doing this because I felt it was wrong.
I've also gone on Omegle and ChatRoulette dressed up to see if I can fool anyone. I've had conversations with guys who had no idea. But each time I would pair up with a woman(or multiple women) they would figure it out immediately, every time. Don't think I have ever fooled a woman. Guys were a bit easier to trick. I remember these two guys one time, I talked to them for about 20 minutes until one of them figured it out. He said "Hey man come back, I think this is a dude".