PSA/warning: THIS UNLOCKS ALL THE CLOTHES AND HAIR STYLES!
Fucking hell. Even after removing the file they're still all unlocked. Only wanted the working extra pack.
Oof. And deleting the save file (I believe it's TKAClothes.sav now) would of course reset you to nothing... but there is a way around this!
To recover your progress:
1. Go to Jodi's Office while you have everything unlocked.
2. Open your backpack, make sure you're only wearing clothing you're "supposed to" have, then hit "Remove unworn clothing". This step might not be necessary, but ensures that no unwanted clothing sneaks in.
3. Go to the mirror and individually right-click and "Put in backpack" for
every clothing item you remember having before.
4. Close the game, delete TKAClothes.sav (located in %LocalAppData%\TheKillingAntidote\Saved\SaveGames). This will remove all clothing unlocks.
5. Go to Jodi's Office again and visit the mirror to save all clothing items in your backpack.
I didn't test this just now, but it worked back when clothes were in HyperBox.sav, and I don't think anything has changed that should prevent this from working now.
EDIT: Unrelated, but best change of the update (that I've noticed so far):
Skirts and garter belts are no longer mutually exclusive! This is featured in the new outfit set, but was also applied to older items such as those pictured above.