Re: Old Glory, slightly moldy. What to do?
Bleach is a BAD IDEA. The flag will come out pink, sky blue, and blotched.
Oxyclean, often called an "oxygen bleach", or an enzyme cleaner from the supermarket shelf, will probably take it right out. When in doubt use warm water, not hot. Liquid Tide is often very good at removing stains, on a par with Shout! and the other stain cleaners in the supermarket. Anything that says it is meant for "grass stains" probably will do well.
No reason to get extreme and burn the flag, yet.
Every year someone gets in an uproar when uniformed paramilitary youth groups hold flag burnings. That'd be Scouts taking care of the worn flags in your local county park.