Hi,
Christine has really good suggestions. I have been taking pilocarpine since about my 5th week of radiation, and it seems to help. Luckily I haven't had the unfortunate side effect of excessive sweating like some people have mentioned.

I also use Mu-Gard oral rinse every night before bed, throughout my radiation treatments and even now (<2 months post rads). This seems to help keep my mouth moist enough through the night.

Good luck to your husband!