Hi
The best home made thing I have found is to take a freezer bag or sandwich bag and put a small slit in one side. Make it long enough that you can reach inside the bag and pull your ouch through it. turn it where the opening is down and it will keep most of the water off. If you run some tape around the upper end and sides of the bag it will keep your pouch and wafer dry. After the shower you can pull the tape off and reuse the bag. It works for me anyway.