I don't think that there is any "natural" form of pain management. Mouth sores are to be expected with the chemo regimen that you are on. Oxycontin is pretty strong stuff but, IMO Duragesic (Fentanyl) patches work better. For one thing, they last 72 hours and give a constant pain management. You will get other narcotics for breakthrough pain, such as Morphine.
Ice chips should give you some relief as well.
Don't use lip balms that are petroleum based. I used Epicren Lip Balm and had good success with that. See:
http://www.amazon.com/Epicuren-Enzy...amp;s=hpc&qid=1210622884&sr=8-27It's available through Amazon - purchase it through the OCF Amazon link and a small percentage goes back to support OCF.