I'm 3 years out from radiation and chemo. Olive oil burns my mouth because I don't have any functional saliva producing glands.
I can't eat solid foods either because there is no saliva to create the bolus to take the solids to the back of my mouth and down the throat. I use the XEROS Dry Mouth Pump all night to wet my mouth. But my dry mouth is permanent and chronic so the dry mouth pump works extremely well for me.