Vinegar and warm water, then run it with the heating function on and you good to go. I mostly mix 2 parts water, 1 part vinegar. Works on everything, vaping stuff, household items, bottles glass/plastic, jewelry and even fresh vegetables, wouldn't run it for too long tho lol.
I use the isonic p4810 and while you can purchase cleaners for these, I go the more natural route, even if you would forget to rinse your items (who would tho, but just in case) you wouldn't have to worry, vinegar has not killed anyone yet, or at least I've never heard of it. But side effect, it cleans and keeps ur ultrasonic cleaner clean as well, and removes odor for cases were your ejuice spills or some of your tanks weren't rinsed good enough prior etc.
Thought I threw that out there, even tho I'm not crazy chef or r055co