Paint and finish drains out through the cooling rack into the cookie sheet.
The most responsible way to dispose of old paint or finish cans is when they are empty and dry. I’ve come up with a way to speed the process along. I bought an inexpensive cookie sheet and cooling rack, and I spray the sheet with WD-40. I place the can upside down and let the remaining contents drain through the rack onto the sheet. The can dries quickly once emptied, and after a few days I use a spatula to scrape the dried cookie sheet clean.
The WD-40 prevents the waste, like this rolled-up varnish, from sticking to the cookie sheet
Instead of using WD40, couldn’t wax paper or parchment paper from the kitchen be used? Then I wouldn’t feel like the cookie sheet would be ruined for using later for food.