It's been hot out here in the desert. Someone sent me a link to this youtube video and I said "Oh, I'm making one of those."
The tripod came together easy: 3 boards (2x4x10'), a 1/2" threaded rod (12" long), and a couple of washers and wing nuts to hold it together. I also got some screw-in eye bolts and paracord.
I tried just hanging the bucket by its handle, but I got nervous about suspending 30-40 lbs of water directly over my children's' heads, so I made an OSB platform for the thing. I think I'll have to try again with a sturdier container. You can see that this one gets all squished.
I just had to drill two holes in the bottom to install a toilet tank kit (the fill valve and the flapper). I used a fitting to adapt my garden hose to the toilet supply line.
The only real trick was the trigger device. I used a piece of steel and a 3/8" rod I had laying around. I tapped holes through both so I could hold them together with a threaded screw. At the other end of the rod, I clamped a pair of vise grips on the rod and hooked it to the flush lever of the toilet kit.
When you hit the target, it swings the steel lever, turns the rod, raises the vise grips and it empties the bucket on top of whoever is in the chair!