I am a big fan of Casey's Super Blue...it gives me great results. Especially if you don't follow the instructions and do the final rinse with water to stop the reaction...I usually do two passes, the first you rinse with water, then a second dose for a little extra darkening for uniformity, then to stop the reaction I use Rem Oil. Having an air compressor is very helpful...but with a receiver cover, it should be pretty easy to get dry even without one.
Also, it helps if you heat the part up with a hair dryer before starting.