Parkerizing just doesn't work on smooth, bare steel. You will get little to no reaction, and the results will not be satisfying.
You can acid etch the steel with a 50% mix of Muriatic acid (hydrochloric acid) and water for a few minutes until you get a nice satin finish. Don't overdo it though. Rinse well in plenty of water and Park right away, as it will rust fast if left wet. I have used this with good success, though I prefer the blast method.
(REMEMBER- add the acid to the water)
Muriatic acid is cheap and available at hardware and pool stores.
Also, remember that the acid is very powerful. Use eye protection and good rubber gloves in an open, fresh air environment. Don't breath the fumes. Use it in a glass plastic or ceramic container. Don't wear any clothes you aren't prepared to ruin.
Be careful and it will work well.
Reminder. Do not dip parts that are parkerized into the Muriatic acid solution. It will not work properly, and probably ruin your parts. Check a part by using a Qtip with the acid solution. If it removes the finish, it is blued. If it doesn't, it is parkerized.
Blued parts are OK, and it is a good way to remove the bluing.
Also, parkerizing is not a coating, there is no adhesion per se, it changes the outer layer of the metal.