I mix 1 table spoon of the wood bleach to a gallon of hot water, works very well but you do have to be careful with chrome if the chrome is in poor condition or its a cheep chrome job it may cloud it. to do bigger stuff like the OP's exh manifolds etc.. it would probably take a day or two, you also want to agitate and mix the water every 8 or 10 hours since the powder settles.
