I think it best to wait until after his mouth heals some before starting the brushing of the mouth. Use the mouthwash and it wil help a lot. Can you get him Magic Mouth Wash? That is one thing that refreshes and numbs.

Since posting this. UPMC, Pittsburgh, Oct 2011 until Jan. I averaged about 2 to 3 surgeries a week there. w Can't have jaw made as bone is deteroriating steaily that is left in jaw. Mersa is to blame. Feeding tube . Had trach for 4mos. Got it out April.
--- Passed away 5/14/14, will be greatly missed by everyone here