Thanks Loli. I must try the juicing. The corners of the mouth are sometimes as issue for me too. My GP recommended zinc ointment to protect them from my saliva - I had thrush at that point too. The dermatitis went from the corners of the mouth and extended down the wrinkles on the side. Not a good look but it didn't last long.
I have heard that water dries out the mouth and gel certainly helps and last longer than water. However, having water also helps me speak more clearly. It seems to irrigate my stiff tongue so that talking is not such an effort.

My teeth were already problematic and the radiotherapy finished many of them off. Seem stable now though. I have enough to hold a partial metal denture.

We don't use the fluoride trays in NZ as a rule.

I keep meaning to do more research into Xylitol which sounds almost as good as fluoride and better for us, maybe? Best wishes.