I don't allow head rubbing. A friend's horse does it and I find it painful and uncomfortable and I'm also super clumsy so I would probably just get hurt. My mare is the only one who would be overly interested if I did allow it anyway, after a ride. She doesn't like her head touched any other time, but once it is sweaty from a ride she likes a face scratch. My rule is once the bridle is off I will scratch her face and she can rub her face on my hands where she is itchy. This lasts about 30 seconds then she is back to not caring for her face being touched. I feel like if I allowed head rubbing she would go for longer, but it's not happening! I do let old man Josh get away with fiddling with his lips a bit more. The others aren't allowed to. King doesn't really try anything to get away with, he is a gentleman. Although he doesn't have the best hips so when I'm cleaning his back hoofs if he pulls or fidgets gently I'll put the leg down and let him readjust. If he pulls hard I'm not so happy with him, but he is usually pretty good and I have learnt where to hold the leg that seems to keep him comfy. Odin isn't allowed anything. He takes advantage of any little thing. I've seen others let him get mouthy becasue it's cute, and then the teeth come out pretty quick. So I don't let him get away with anything and we don't let people handle him who will to be safe.