If you are starting with new traps, I wouldn't bother trying to rust and dye them. I run my new traps through the dishwasher a couple times and then wax. If they've never rusted, they won't hold the dye. But if they've never rusted, they don't need the dye to neutralize the rust.
After they've made a catch, or rusted from anti-freeze, I power wash them, then boil clean, the boil dye, then wax. I will not fool around with dirty traps.
Some of my fox traps were treated with petroleum dip, then as they've been used I just treated with rustoleum as needed. Caught plenty of fox with them.