Simple green or easy off oven cleaner will also get the oil off new traps.
Once the oil is off your can put vinegar in water and and spray it on the traps, leave them out in the yard in the sun and they will get a fine coat of rust on them and then you can dye them.
Frankly the first year as long as you get the oil off the traps you can just wax them, and use them. The dye isn't all that important
