My polishing cloth has gotten to the point where it is doing more harm than good. Is there a way I can wash it or something?

If it is a treated one, the answer is no. You are best off getting a new one.

So, would it be easier just to get an untreated polishing cloth? I heard that treated cloths are easier on the flute but I most certainly don`t want to have to buy a new cloth every month or so.

I heard that untreated cloths are better for the flute because you are not using chemicals on the metal. However if there is bad tarnishing the untreated cloths aren`t much good I suppose - just have benefits with regular usage.

I have one of each but prefer to use the untreated one where possible. In the interests of economy the untreated one is clearly better as it can be washed and used again, so it`s worth buying. Mine is good.