This is our favorite option for a poop tube if you don't mind spending a little money. It is bomber, convenient, and a good size for most big walls.
While there are more than a dozen options (and even more names), this is the best waste storage option for most big wall climbers. If you have the time and want to make your own you will save money. But you can't beat the convenience and bomberness of the Waste Case.
View more on making your own poop tube.