Would boiling water kill microorganisms in clothing that had feces spilled on it?
Using boiling water alone will not destroy all the toxic compounds found within faeces. One example is skatole, this is found in faeces and is partially responsible for the foul smell faeces gives off. By laundry I assume you mean laundry detergent? If so, it would depend on the detergent being used.

I hope this answered your question :)