If you're still searching for some relief to oral Mucositis, then try a mouthwash called 'Caphosol'.
Having got the box and info. leaflet in front of me,I'm sure it's available in the States. Over here it's produced by EUSA Pharma (Europe) Ltd, Oxford,England,UK. However, the box does contain a depiction of a map of Europe in addition to North America, so you should be able to track it down.
I have had 6 weeks of chemo/ radio last year, and then 18 weeks of chemo this year, so all of the previous posts on this topic are familiar to me. Caphosol will not wipe out the mocositis, but it certainly alleviated mine. It was recommended at a private 2nd opinion I had at a regional Cancer specialist unit. My primary Oncologist didn't seem to know about this product and it had to be specifically ordered.
We all get fed the line that we're all different and respond in different ways ( etc etc ad infinitum) ,but it's worth a try.