This is what they were for.
Ya threw all of your mixed up crap in them, stuffed them under the bench or on a shelf for emergencies and then went down and bought new shit just for the project you were working on at the time.
I swear I want to say I saw some brand of coffee within the last six months that was in a metal can instead of those plastic tubs it all comes in now.
Otherwise the only way you can find them is at garage and estate sales.
I picked up two a couple months ago.
I am holding on to those bastards like they are gold bars too.
For the other reason they were handy.
Cleaning small parts in gasoline.