Is there anything you can do with clothing that is on low percentages? I can't seem to sell any of it to bulk goods traders; is there a way for me to break them down for cloth, or even destroy them so they don't take up room in my stockpile?
exotic goods trader will buy them, but thats all you can do with em, bar burn em up in the crematorium.
OR use a mending mod and repair the items
Don't forget you can designate a high priority stockpile for apparel and set the remaining allowed % to be super low. I use this to separate the tattered clothing I have and just let it rot away outside.
You can do the same thing with a crematorium as well, like skully said
I usually make a separate stockpile somewhere in a place where these things won't get in the way, add a trade beacon and sell it once the exotic trader comes.
Fastest way to just get rid of it I think is to use grenades or Molotovs to put them on fire/burn them up. Draft a colonist and tell them to attack area (another reason it's good to keep it outside your base since they often miss the target with grenades)