Wow thanks for all the info @thanrose and even experimenting on the label removal with the goofoff and furniture stripper as well as nail polish remover/acetone! I had no idea I would find a dedicated expert on these yellow kitty litter buckets here
I also noted the interesting wave-form bottom design and was wondering how to take advantage of it. Yay! ...And yes to both thanrose and ElizabethB, I also make holes up the sides of tall containers. I think that makes all the difference.
Painting or stripping the labels off chemically -- the fact of the matter is I am -keeling over and overcome by fumes- sensitive to volatile chemicals, so I really appreciate the experiments and suggestions, but haha I don't think I will. If they don't come off with oil/grease, alcohol, or soap, they are "dead to me" -- I just won't see them, so there. ha. So, I think I will develop familiarity-blindness like you, thanrose, and leave the labels as they are. I don't think I will mind.
I'm going to try making at least one set of stacked SIP with these. I've been wanting to, but had limited number of buckets until now and wasn't entirely sure I wanted to make holes in them.
The bright yellow color will be useful for making them easy to find, and I agree they would be fabulous for all kinds of storage containers. The rectangular shape creates all kinds of possibilities. I will have to think about how to allocate them.