I did a lot of chipping on the 1/35 Tiger Tank model I built a couple of years ago:
The 'chipping medium' I used was hairspray. It wasn't hard to remove, but I had to experiment a fair bit to get the right amount of hairspray in the right places before the effect felt good to me. I applied the hairspray by stippling it on with a rough brush, then used acrylics in an airbrush for the various layers.
I wouldn't use black primer as a top coat over the chipping medium. Primer is designed to stick and be as resilient as possible. You might find that it soaks through the chipping medium and you can't remove it anywhere. That said, you can always experiment on pieces of scrap plastic or whatever and find out!
If you are interested, here is a list of the layers I applied to get the final effect on my Tiger. Now, bear in mind that this is a scale display model, not intended for gaming.
primer
hair spray
German grey base coat
washes
gloss coat
decals
matte coat
more washes
dirt
another matte coat
hair spray again
whitewash
many more washes
pigment rust
pigment dust
streaks
graphite metal details
mud
90% of everything listed up to the whitewash was hidden by the white, but I wanted it to look 'right' wherever I scraped away the whitewash, so I had to do it properly!