No, I don't mind about the siggy thing, it's funny.
I use a piece of plastic wrap and a rubberband to keep stuff out - I use one to store collected rainwater and the others for my tank cleaning. The narrow neck keeps the hose in place better than using a bucket and less sloshing on the floor when you are hauling it half way across the house.
Yes, both sell them with water in them and so do most grocery stores - but they've gotten expensive! They are at the front of the store and were running about $13.00 each last time I looked. I think that some wally world's sell them (with water), as well. Tractor supply sells food grade containers, again they are a bit expensive. I seriously considered getting one of the bigger ones, about 90 gallons or so, to use as a grow out for my dempsey's. It's still a serious consideration when we redo the basement and add the fish room. It's cheaper than an aquarium, definately safe for the fish as it is food grade plastic and easier to store when you don't need it.