USP glycerine from the drug store, and plain old water. Mess around with the ratio till you get something that feels right. A fraction of the costs. (Read their label, that's what it is) I did this right after treatment for a year. Don't swallow it, swish and spit. It will coat the soft tissues for awhile. But these days I'm a Biotene guy, I think it's way better than Oasis, and it has the enzymes in it that will help protect your mouth from bacteria at the same time, not just moisturize. The Biotene oral gel in the tube lasts a long time, and I use that at night. The liquid Oral Balance during lectures when I can't be stopping to drink every few sentences. The rest of the time, like most of us, I have a bottle of water in my hand.