I seriously doubt that a professional barber would do that.
1. None of the standard textbooks for barbers cover waxing - it isn't something that real barbers do. Only beauticians/cosmetologists do that.
2. I have spoken to professional cosmo's that do waxing and none of them would do the head. The hair there is too dense and you can do real damage to the skin of the scalp. It can cause fine scarring and small "dents" or pockmarks.
3. And oh yes; guaranteed to be painful.
4. In most States of the Union, numbing cream may only be used/prescribed by a licensed physician, (although I do know a few tattooists who have managed to get their hands on a jar of the stuff)
5. My laser doctor uses numbing cream on my skin 30 minutes before each laser treatment. It still HURTTSSS!!!!!!!