I never tickled with or been tickled by a hairbrush, but I saw people in vids getting their feet tickled with a hairbrush and I know I'd love receiving it from a female 'ler, yeah. As for teeth...I think that wouldn't do much, would it? A tongue would do more. Teeth are hard but I can't see how they are protruding from the mouth enough to tickle someone effectively. But one time I was licking a girl's soles and she said, "Let's feel those teeth!" So she no doubt liked the sensation of my teeth on her soles and it probably tickled, even though she didn't laugh, but then you don't have to laugh when you feel tickling sensations either. But the answer, overall, would be the hairbrush.