Chris,

It depends on how bad it is. I had a towel with mildew that actually
stank. I washed it several times to no avail. I put it on my truck as
a rag, I still couldn't get the smell out with repeat washings. I
finally threw it away, it stank to much to even use it for a shop rag.

Try washing them & see what happens. Maybe you will do better than I.
Good luck.

Stretch