Try 99% isopropyl alcohol. They keep it behind the counter at the drug store, so you’ll have to ask for it. The 91% you get off the shelf will work, but the 70% not very well. It’s relatively non-toxic (don’t drink it) and works wonders for both cleaning the build plate and in loosing up stubborn pieces that won’t come loose. Of course you’ll smell like you’ve been drinking, but you’ll have proof you haven’t, no pun intended. I should mention, not to use near an open flame, or get it on your skin or in your eyes, dugh!
Aqua net hair spray can give a more even, predicable coat of adhesion then glue stick, plus it cleans off great with the alcohol.