Tire mounting lubricant
Suzuki DR350 motorcycles, 1990 - 1999.
Buy O-rings for your DR350. Good quality + low prices.
In the past I've used all manner of lubricants from soap to WD-40. I never had any trouble with any of them, though I was always careful to wash off the excess.
Several years ago I bought a gallon of the real stuff and I've been using it ever since. It is inexpensive, lasts a long time, and does a great job.