I rarely if ever use acetone to remove adhesive, stickers, paint, etc. I almost always use WD-40 and it again worked spectacularly on these buckets, when coupled with 0-grade steel wool. After removing all of the Tidy Cats graphics, I sprayed each with full-tilt Simple Green, hosed them off, then washed with soap and water. They came out rather decent if I say so myself.
I didn't have enough stickers on hand to make them look super cool, but I did get started, at least.
Reflective tape is on the way to my house as we speak, in the interest of visibility.
Last picture censored for the sensitive folk.