I have had good luck with the slippery Elm bark. Not so much in the mouth but more so in the back of my throat.

Not wanting to change the subject but....with the use of Manuka Honey I have not had a sinlge mouth sore after 5 weeks of rads (knock on wood). Granted, most of my rads are aimed towards the back of my throat where my tonsils used to be but there is still some scatter and (although I can't be sure) I do think it has helped me a lot.

Will Zinn