I went through 33 sessions of radiation at the end of 2011 for HPV16 related cancer on my tonsils.   My radiologist recommended Caphosol which worked out very well for me.
I have a friend who is just started radiation/chemo for an 
HPV-16 positive Squamous Cell Carcinoma of the Nasopharynx.
I am recommending it to my friend however I want to see if others have had similar positive experiences with Caphosol  (or was I just one of ht elucky ones)  It is pretty expensive and I know that some insurance companies don't cover it .   
Any advice (positive or negative) is welcome 
BTW - I am free and clear (three year anniversary).  I am one of the lucky ones as no side effects and life is treating me very well.    This forum was a bright light in a rather dark space for me.  I really appreciated all your help and good wishes.  
Thanks - Steve