I use, and the book by the late Mr. Brownell says, Lye. Ace has red devil lye. Use it 50/50 with water, soak hardware and/or all steel parts in a plastic or metal container for 3-5 days. Stir/shake it once in a while. Hardware comes out clean as a whistle. If it's warmed in a metal pot it is more effective he says but NOT necessary. You will be amazed. Wear goggles/gloves when messing with it and when final washing in water. Put a weight on the lid of the plastic container and lock it up while soaking. You don't want Kids or animals to get at it. Mark the plastic container with POISON label. Dispose of it properly. It's made for drains so it's ok to dump down drain. Some say you can use Drano. I, too, use most of the hardware over again. The strength is still there. Chase all threads, male and female. If the lock washers are flatish, don't reuse them. They need to have the normal split/stick-up or the spring loading is gone. I also use a wire wheel on my bench grinder to clean hardware. I get the hardware at a hardware store
