I’ve seen both the washer tub and wire kennel in action
We’ve got a wire kennel at our cabin now. The downsides I see are 1) it rusts 2) it catches every bit of aquatic vegetation that washes to shore. Otherwise, it serves it’s purpose well. I have had friends that use the wash tub. It works great, but you’ll need to find some type of cover for it.
One night, I watched a bowfin swim up to ours that had some sunnies in it that my nieces caught. It was persistant in trying to get them, but it never could figure out how to get at one 