I was able to remove the annoying yellowing effect from old white and lightgray bricks wiht the usage of hydrogen peroxide. With great results I have to say . Now I wonder what to do with the remaining fluid. Is there a danger to poison someone when use it in my household? Is it ok to drain it down the sink? Any advice on how to deal with it is welcome.
Another thing, when do I have to change the fluid? Will the effect gradually decrease?