Good how to.
I use muratic acid/water 50:50 mix often on smaller parts. Don't put any Pot Metal in it though. Don't ask how I know...
Molasses/water 1:10 mix works without harming metal. Molasses from the local Co-Op mixed with water in a 55 gal drum. Takes a lot longer but I put lots of parts through it and leave them in for weeks sometimes.
There are some YouTube videos of guys putting whole car fenders in molasses/water, even whole old steel car bodies in it. YouTube is where I found it.
