To get a clean butt in 4 wipes, you should start the process with natural materials.  As Mike Clelland explains in his book, you can usually find snow, pine cones (be selective), sticks, bark, leaves, grass or stones to start the cleaning process.  That way, when you pull out your half a shop towel, you are down to what we call ‘polishing’.  The graphics handily printed on one side of a towel in the kit show you how to get 4 polishing wipes out of one half of a shop towel. 

Before leaving on a trip, cut the shop towels in half.  We recommend taking one piece for each day, but you should be guided by your personal experience.  Include the half with the printed instructions, and save that for the last use.  By that time, you should be an expert at the offal origami.