Pressure wash as soon as the weather breaks...then lay in the yard another month. Or so....then dye and wax....going to try to do mine in the spring and hope they are OK come fall....working out of state is tough...once i get home its bow season or later...some years its been time to go bear huntin...
If traps are rusty, have unknown dips/dyes etc on them and you wanna take them to bare metal and start over, which is what i do with most used traps i buy, pressure wash, then boil or dish wash if still waxy...then soak them in vinegar for a week or so depending how bad they are...then pressure wash again..do you work...then treat them
I take mine to the car wash as stated and get rid of as much grime and mud.
Then I tune them up, and boil them for a couple of hours at a full rolling boil with a half can of Drano crystals (You can get them at WalMart or Lowe's).
I let them rust for about a week, then dye and wax. Store them in a rubbermaid tub with a snug lid until season. I do mine as soon as I can in the spring, cause I always seem to be running behind come season.
Bodygrips and DP's get hosed off and a fresh coat of paint.