I find a small, angled eyebrow make-up brush to be very effective on me. The hair brushes actually don't tickle me...I think they are to rough...he isprobably more sensitive to light touch if he is feather sensitive. Oh, and try baby oil on his soles too! Wear some rubber gloves...it's crazy!
If I may add a suggestion, I was in an art supply store in another town a little while back (hope they didn't get flooded out). I saw some rather interesting oil paint and watercolor brushes which looked as though they might have potential!
If you do use a hairbrush, the ones with the little nubs at the end of the bristles will likely be 1) less rough, and so b) more effective, and probably ones where the bristles are spaced out a bit. Just go and have the most fun speculating anyone ever has in a Walgreen's hair care aisle. 😉
Try and find a wooden double sided hairbrush that has bristles on one side and wooden nobely bits on the other for massaging! It's the massage side that will really tickle! But most of the suggestions that you have been given have been great, hope this has helped? Happy tickling!!
i've always thought the hairbrush idea would be too rough... the artist's brushes should work... and i would think an ordinary paintbrush... unused of course... would be quite wicked... thousands of those soft new bristles at play... ooohh
I believe it's all in how you use the hairbrush, really. If you're gentle and light with it, I'm sure it'll drive him nuts.
Would recommend baby oil if you're going to try it, as well as starting off slow/gentle. If going faster tickles more than it hurts, then that's great, but, well, definitely take into account what others have said.
I think a brush that is worth while to look into is a make up brush, though.