Review (3/5): I used this t for grout and mold on silicone seal.
I had high hopes for this but I did use it for my washer because I already bought a new one.
I used this for both the grout in my bathroom and the moldy silicone around my bathroom tub faucet, I did not have great results on either, I tried several applications and same results.
I can’t say this would not work on your washer seal since I was not able to try it out on there.