So I just learned that those funky mutations are sourced from the blob and that zombification was just an variation of the blob’s mutating ability which explain how zombies can evolve to have various special abilities.
I though that there may be a research related to using purifier to at least purge the blob from the host (albeit leaving a corpse). Even if they can’t ouright be taken down by the purifier there’s gotta be some kind of lloyd charm effect that prevent zombies and mutants from using their special ability when exposed to a de-concentrated purifier gas.
Now if the argument against is about niche application and inefficiency, i’d argue for it. Mutagen can be cheaply made using zombies themselves and converting them to purifier is even cheaper since it uses common household loot. A more concentrated purifier can be delivered like a toxin via darts, bolts, or even arrows while a lesser ones can be delivered by a chemical sprayer.
There could be a balance which causes this to backfire toward mutated player and monsters alike the same way it could affect zombies. And some zombies such as the hazmat, firefighter, survivor, and flamer zombies can be entirely immune to the effect of purifier gas due to their body coverage. Those type of zombie exists for some reason despite of the fact that no elemental weapon aside from acid can affect zombies
Additionally I do have other issues on how radiation gives you mutation instead of cancer despite of the lore stating otherwise but that seems to be fine for me since that feature is optional.