Spit naturally dissolves, so it cleans well, and fast too. It’s not not harmful to any common materials afaik, it’s always immediately available. You need some way to wipe it off of course, just like with any other cleaning agent.
Just don’t let others see you, cause they’d be grossed out.
(Well it might be a little unhygienic, which is why it’s best as a quick/temporary solution, and you can do it properly later)
Huh, I had no clue this was a proper thing. But if you want to increase your tolerance, try spending more time around dogs or little kids