That's why I don't even bother with scraping palys off, if I can I'll chip off a piece of the rock with them on, if I can't, I toss it into the dry rock pile. Won't get rid of palytoxins but presumably they won't have aiptasia like regeneration and won't come back a year after being out of water
I kalk paste them in the tank - maybe 4-5 at a time. or I like mikes way too. Let them just dry out in the sun, but make sure no dog or animal can go lick /eat them.