No, that doesn’t fix it.
I could, for instance, totally see a player who legitimately had no idea that wearing galoshes was anything other than a style choice finding some somewhere and wearing them.
“Surely by the time they’ve played enough to get command roles, though…” No, even still. Maybe they know but just forgot about it, or weren’t really thinking about it, or knew full well what the galoshes did but picked them up for the look and didn’t really think the mechanical impact would be a big deal.
Conversely, maybe the, er, nefarious powergamer grabs some galoshes and goes “look, there are puddles of blood and slime and all kinds of gross stuff all over the station. Why wouldn’t my character want to keep their feet clean?” Frankly, when you look at it that way, it’s weird that absolutely everyone doesn’t wear them. People on evac shuttles should be collecting all the pairs of shoes and throwing them out the airlock because they’re so disgusting. Shoe-stealing mothfolk should be ending up in medbay all the time for how sick they ought to be getting eating those gunk-caked shoes. Galoshes should be standard kit - that’s what a normal person would want, right?
“Normal” is subjective, and all the other problems with admins not being mind-readers still apply here too. You can’t distinguish between the player who wears galoshes for innocent reasons and the player who wears galoshes for mechanics-motivated reasons but can easily come up with an in-character justification for doing so, and this rule will either fail entirely to stop the latter, cause unreasonable trouble for the former, or both.
I don’t think there’s any rephrasing of this rule that’ll fix it.
If anyone reads this and still isn’t convinced, I’ll post my argument for why it’s the player throwing soap to slip someone, not the galoshes-wearer, who’s the real powergamer in this example.
(Really, examples don’t cut it. People can post examples ad nauseum of problems that this rule is supposed to fix, that are seemingly clear-cut cases of bad play. The fact that those examples exist does not address the problem with this rule.)