With the help of the mod Improved Trading Version, you may now sell practically all of the trash that was previously impossible to sell. Examples include sacks of blood, rotting flesh, and stone tools, among many others. Additionally, you can sell practically everything in units of ONE, which means you won't be stuck with crap that takes up a full slot in your backpack if you're attempting to make room for nicer goods.

For instance, if you need to, you can only sell one rock! Dyes are an exception, but you can recycle them into paint to make a product that can be sold in any number. Likewise, seeds are an exception.