Long story short, I have a lot of pitting on my Glock slide from daily carry over a couple years. I bought the gun with the NiB coating already on it, and would like to strip it completely and refinish it (probably even do a slide melt, so I'm not too worried about aggressively removing material ). I'm thinking of going with a magnesium phosphate park, though I don't really know what the best process to remove the nickel is going to be.

I'm fine with just sanding it a bit to get some grit for something to stick to it, but I'm not sure that's going to be very consistent. I'm just sick of the nickel, it tarnishes after a day now and I gave up on maintaining it, I just want it gone. Any ideas or recommendations?

Here's some before work gore for you to see what I have to deal with:

Well, it kind of sounds like you need a professional, but, Glock slides are cheap if you eff it up.  Might want to spend some time on caswell plating site to see what chemicals they sell to do nickel stripping.

You could probably sell the slide as is for $100.  Combine that $100 with the same time and money you'd need to strip, profile(melt), re heat treat after the profiling and refinish the existing slide and come out even or up on a new slide from Lonewolf or some of the other options out there.  I'm sure someone like me would be interested in that slide for a polymer 80 build and with a basic cerkote treatment would be happy enough.

Blasting it with Copper slag will take that off. It will take a minute but it will come off. That said Glock slides (from experience) are not a item that I would parkerize. You could blast it and Cerakote it.

Thanks, I was actually able to get it sent in for warranty work after a bit of persuasion, and they completely redid the nickel boron.

Since you already have history with the NiB and didn't like it, you might as well sell it now while it looks good and buy what will serve you better long term.

NiB doesn't like Hoppe's or other copper solvents. It dissolves the copper used in the base coating used in many NiB applications and causes the finish to come off.

I have a chrome plated Remington 1911 that has the finish coming off for the same reason I suspect. Need to refinish it one of these days.