Today I found a towel on Trouble's playscape. I have no idea how long the towel was out there but it smelled like it had been out there since Halloween.
To de-stink towels or any laundry for that matter, try vinegar. It's not just for your pancakes!
Also: Try adding a cup of vinegar into your washing machine and run it through a normal cycle without clothes. This will freshen up the washing machine, clean the hoses, and unclog soap scum.
Check your laundry for stains and remove them first, as vinegar may set them.
Wash like colors together.