I’m working on growing potatoes (with an “e”) in 5 gallon tubs this year. I’ve been collecting tubs off the sides of the road (bleaching & cleaning them as I go). It’s new territory for me, so we’ll see how it works out.
I wish you luck with your taters. Soapy water with some bleach is the ticket with any containers, especially if you’ve found them, but a good practice with all containers.