We tried to make our own version of the Emergency Essentials Toilet. We bought a wood toilet seat and cut a groove in the underside with a router to fit a 5 gallon bucket. This was not a very good idea, because the resulting seat/bucket combination was top heavy. You really don’t want a toilet flipping over…
So we purchased a seat/bucket combo from Emergency Essentials, and they sell something called “poo bags”, or double zipper seamed bag with some powder/biochemical compound that deodorizes and decomposes human waste. The seat is small and awkward to use on a five gallon bucket, but it works.