I agree with the redirection, and I think it is important to enforce the rule that he cannot get his stimulation from hurting you or even touching others when they do not want to be touched. It sounds like he wants soothing tactile stimulation. I agree with some kind of soft lovee or stuffed animal. Would he like a bean/rice box with toys inside to dip his hands and play in? My DS (3, seeker) pulled my hair with force and aggressively for a long time and still does when he is frustrated. He did a lot of other aggressive behaviors like biting, pinching, slapping, etc. me mostly just to get his stimulation- he would be laughing and smiling- or occasionally out of frustration. My DS touches strangers and kids at school too much also and needs help with boundaries (he can say hi to stranger kids at playground, hug kids at school, but only kiss family members, and things like that).