J.W.
What's worked for me is ...
1/2c color safe bleach - poweder
1/2c dishwater detergent - powder
1/2c laundry soap - powder
(they all can be "generic, no name brand needed)
dump those in a 5 gallon bucket, add some hot water, stir it a round some, put whatever clothes in, then let them soak for 12-24hrs.
You can have whites and colors mixed in together and it will not cause any problems.
Put them through the washmaching after .... it's MAJIC! Works on clothes, my girlfriend used it on all her "nice" table clothes that were stained ... I used it on all my pregnancy clothes (got out all those belly stains from the last baby)
So here's the first idea.
good luck