You've asked a very difficult question and you're seeking a fantasy that's very rare. Some women want to be tickled 'til they cry...just like some women want to be spanked until they cry...from what I've seen so far, the majority are not like that.
The very word "torture" attached to your "tickle" might just be the problem. Women like to be seduced, teased, made to feel young...not too many want to cry to feel beautiful or loved...what ShadowTickler said is somewhat correct...you will get in a lot of trouble if you persist too hard when you tickle someone. Especially if they're vanilla, to them, 30 seconds of tickling could be a lot and 5 minutes might be way too much.
Best advice...you want a woman who likes to cry from tickling...you need to post in the personals...you don't need to get "escorts" but if the woman who answers lives far away...one of you should fly to the other to share the fantasy.
Maybe after your itch has been scratched a bit...you'll either fall in love with each other...or maybe your needs will mellow out and you can fall in love with someone more vanilla.
I want to re-iterate. NOT MANY WOMAN WANT TO CRY...IF THEY DID, I SUSPECT MORE WOULD HAVE WRITTEN IN BY NOW.
Mistress Stephanie Locke