I'm not familar with it, what is it made out of?
If it's just a nylon bag and they don't recommend the wash machine, hose it off first, then dunk it in a bucket of mild soap, hose it off again and dunk it back in a bucket of cold water to really rinse it off, then let it air dry.

If you don't want to stand behind our soldiers who are in danger zones, please stand in front of one.
VanHalen 25 yr QH Stallion R.I.P. 4/11/82 - 5/8/08 24 wonderful years together.
Scout 23-25 yr Paint Cross Gelding
Glistening 9 yr Arab/Saddlebred Mare