Old toothbrushes tend to melt with the gun cleaners though. I use them for other garage stuff.

Lunch meat containers for sorting brass and other reloading functions. Dish pans too.

Old cat litter box lid is large enough to drain engine oil into. (2 gallons or more)

Plastic sheets from the shipping pallets, make a great driveway slider for working under cars. (much like having a creeper) easy cleanup too. Wipes clean of oil/grease.

Tons of other things I can't think of right now.