Merri, dry mouth is one of the annoying side effects OC patients have post rads. In time this does get slightly better for most of us. It just takes a long time, much longer than most patients expect. After everything cancer patients go thru with OC, it takes 2 years for a complete recovery. The dry mouth and sense of taste are the 2 main areas where patients will find improvements every so often right thru 2 years post rads. We have even had a few members relate they have noticed improvements even at 2 1/2 years post rads.
As far as the dry mouth goes, what your husband is experiencing is normal. Many patients have dry mouth issues while going thru rads, even more-so afterwards. Using a humidifier can help. Some patients find gum or candy with xylitol helpful. Others use some lozenges that they stick to the roof of their mouth and it slowly dissolves (helps overnight). The rinses for dry mouth dont always work as well as they advertise. Especially the Biotene products which have undergone a major ingredient change that makes their products a waste of money. Ive added a link to the Biotene thread where there are many good ideas to help with dry mouth and other products discussed.
You can also try using the search function which is near the upper right corner of any page. You will find hundreds of posts about dry mouth.
Best wishes!
Biotene thread