Hi Derrick,
I have never found a good solution for this problem with rags or with my cover-alls.
For rags I typically start with a clean one and use it for a job until it "graduates" to a "slightly dirty rag". The slightly dirty ones get used for first-layer degunking, etc. and then "graduate" to "dirty rags" at which point they get used for jobs like cleaning oil spills off the floor. Then they "graduate" to the garbage can. Note I keep old oily ones in a sealed metal bucket away from "flammables" until garbage day when they get taken to the curb.
It is rather less formal than suggested above.
Similarly for my coveralls I have a few pairs that "graduate" down the line of filth. The last step is usually changing the oil or dumping transmission pan before they are used-up.
Luckily I simple ask for another pair for my birthday, or x-mas, or fathers day, etc.
I learned early in my marriage not to try washing them.
That first time I spent too much time washing out the inside of the washing machine!
-brino