Can tickling be a good punishment for goth/emo people?

My friend's sister is goth kida emo she dresses in black any everything and is really serious. Anyway, she acts really mean with me when I'm at her house and last time I had an argument with her and she took a sweater out of my bag and kept it until yesterday when my friend found it. He said I could come there and we would find a way to pay her back, I don't really want to hurt her but I want her to understand not to keep doing that kind of thing. She doesn't listen if someone just tells her. My friend wants me to find a way to pay her back and I was thinking, since she never laughs and acts serious, what if we tickled her, and I already know she's really ticklish. Do you think it's a good or bad idea and do you have other ideas?