Yep, the dishwasher will do the job, but few are brave enough to try it

On your body grip traps, skip the waxing or you will end up with some sore fingers and hands. If they are mostly going to be used for water sets, all I would do is Speed Dip them.
The 1.5 footholds can be either dipped or dyed and definitely waxed. Not all my footholds are waxed, but I like the speed of the ones that are waxed compared to those that are not.
If you are not going to use the traps this season, I would wait on the prepping until later in the summer or very early fall. Rust is good, but too much rust isn’t so good 