The best advice I can give you so there is not a battle with bad habits learned, Is call your vet and see if they can come out and give him a sedative. Those burrs are painful to remove. I had a mare get into them one winter and it took me hour and hours to get them out the only advantage that I had was she was a little mare. At least with the sedative it may slow him down enough that hopefully no one will get hurt. and he won't care as much.

Hope this helps

I don't normally recommend using drugs but some times you need that little extra help.