I agree with a few points made above:
1. wash only the stuff you plan on keeping. I'll bet you dollars to doughnuts when the other organizations receive fabrics, they wash them too, so it's probable the fabrics are being washed multiple times.
2. delegate! ask for volunteers. If you struggle to find anyone to help, maybe make it an event or party with a couple of snacks, drinks, and silly little door prizes from the dollar store. If it becomes a fun social activity instead of a boring chore, you will end up with lots of "helpers".