While shave creams and shave soaps work best with a brush I have given some guys a little shave cream and told them to use it as a soap and work up a lather on their face with their hands. Granted, these guys don't know what good lather is but they said they got good results. Your local Bath and Body Works carries C.O. Bigelow shave cream in a tube. Premium Shave Cream with Eucalyptus Oil - C.O. Bigelow - Bath & Body Works

It's not the best out there but much better than hand/bath soap and isn't expensive. Should work OK for face lathering with his hands. I would work much netter with a brush but one step at a time.

Good luck