I've been suffering with lots of mouth sores due to one of the chemo drugs. I tried using Magic Mouthwash, Rinsinol and Gelclair and got some relief. Then my local doctor suggested I get a 2% Lidocaine Viscous gel, which has worked much better for me. I dab a bit on the sores with a Q-tip and remain pain-free for hours, or I can mix it with a little water and swish. You need a prescription. For those who haven't been satisfied with other pain relief, I suggest you give this a try.