I've always been bored as fuck when a girl insists we try that.
I've seem threads that kind of have what you're talking about.
They normally just go by what people write. For example: I walk into a room and see VlSammi laying on a couch with her socked feet resting over the edge. I sit in the chair next to her in perfect position of her feet and begin to slowly tickle them.
Now you write something in response to that. That's the only way I can see people being able to have a tickle fight via the Internet
Are you sure that was a GIRL?