This is the most indestructible liquid vessel that I know of, the smaller sized ones are made of a softer material that just will never crack under normal use:
Drill it out using a new hole saw bit from the inside out, with the bucket on its side and lying on a flat piece of scrap wood backer, that will help keep the cut cleaner and not crack, but a Brute shouldn’t crack anyways, just best practices for this sort of thing. Let the saw bit do the cutting and don’t press too hard and you’ll have a nice hole. Sand or file the edges smooth and then mount one of these with some plumbers Teflon tape and dab some silicone bathroom sealant on both sides of the washers, tighten it down and wipe away the excess goo.
You’ll have a cheap and basically leakproof reservoir that’s got a sturdy lid and big handles, and you can even get a dolly that locks into the bottom of the Brute if you wanted to!