In my less than humble opinion, high pressure spraying will never be a substitute for boiling. Especially in regards to odors and chemicals (salts) that may have penertated the pours of the metal.
That said, high pressure washing would certainly be better than doing nothing to the traps.
In this particualr case, I believe I would just go ahead and remove those stakes from your traps. Boil the traps in a detergent solution. Then boil the stakes seperately in a plain water bath. Plain old boiling water will remove about 95% of all the contaminants.