as a service guy,i wash over 50 of them a week
-turn them inside out best u can
-rinse off the solids with a hose
-throw them in the wash machine with 2 capfuls(not Cups) of plain unscented bleach
No soap
-let them air dry,no dryer
hope this helps ,i wash about 10 at a time this way
been doing it like this for many years