For what it's worth I used a piece of zinc and electrolysis in a bath of water with a little baking soda plus a little washing soda. Worked well too.
I use an old 12V power supply from a computer, capable of supplying a lot of amps (maybe 24 or so). Got a roll of zinc that people use on the roof, from home hardware. It was the only source I could find of a more reasonable price. It's recommended that one uses distilled water. There are several "salts" that one could use to make the bath, the idea is that the water conducts ions if salts are added. A little bit of detergent like washing soda helps to have a finer deposit for the plating. I also tried epsom salt too. The receiver item should be really well clean of grease or oil, and dirt, of course. Many like the receiver item dipped in muriartic acid (hycrochloric acid). That'll clean most rust too. The plating is simply hanging the piece of zinc in the bath, I try to hang it so that the tape of zinc goes all the way around the receiver piece. Zinc goes on the + (positive) lead of the power supply, and the receiver on the - (negative).
The more proper way is to get the right zinc sulfate from caswel, but what I'm trying to say is that I got a good coating using my method too. In fact I experimented with copper coating of tools too. Now that way I got a nice looking coppery pair of pliers.
When I was rebuilding the carb on my old boat I silver coated the inner parts of the carb using an old silver chain I had around as donor. And it worked, using the same idea as above. Of course to do it more professionally you get silver in a salt powder of sorts, tends to be expensive.
