I got some UltraPure with my last horn and you really need to oil daily with it. The other synthetic oils that I have used seem to last and protect longer. They are not as fast though. Bone dry is critical. Oil floats on water - not a recipe for protecting your valves. Petroleum based oils can be easily cleaned out with soapy water. Synthetics do not break down like petroleum distillates do, sou you have to scrub more!