Since Nexion is prompting me, I'll bite. Steel wool is evil because using it creates a contaminant. Steel wool is magnetic, it conducts electricity, it rusts easily, and it breaks down into little pieces that get into everything - including any fabric or your skin. I don't think it should be used around electric guitars at all. Compressed air just spreads it like fine dust - getting into everything. If you must use metal wool - use brass wool. It won't rust at least. Scotchbrite remains the safe abrasive material of choice in my shop, and it's available in a panoply of "grits". It stores forever without rusting on the shelf. Leave steel wool to the cabinet makers, metal workers, or the kitchen sink.
I think Beau means that creating "metal-dust" around your pickups is not the brightest idea and I think he is right. If you need more details, mention steelwool to Goob. It's gonna be worse than telling GuitarDoc about the input jack of a guitar....
But how about slug coils? I mean, there are videos of people disassembling humbuckers but I have never seen them replacing the slug coils. Is this even doable considering my guitar is wax potted?
First...if your screw poles were clean around the threads, the slugs will be fine also.
Second...if your pup is wax potted your slugs are going to be fine.
Third...unless you're WAY older than I am, or expect to live more than a couple hundred years, your coil wires are going to be fine.
thats specifically about vintage fender style single coils where the wire is wrapped directly around the magnets, the coil on a bucker is isolated from contact with anything but the bobbin
For what it's worth, I've taken a couple of pups down to complete parade rest a couple times, and IIRC, the slugs pushed out fairly easily, with no damage to anything. YMMV.
Here's another idea: They don't need to come out the whole way. Push them up from the bottom so that they stick up the same amount that they protruded through the bottom. Then get one of these: (or make one.)
Place it on top to protect the bobbin. Then use scotchbrite, or whatever people recommend, to polish the top. Then push the bobbins back down even with the top.
For what it's worth, I've taken a couple of pups down to complete parade rest a couple times, and IIRC, the slugs pushed out fairly easily, with no damage to anything. YMMV.