The game gave my sim the dreaded pigtail hair for the sauna, but when i try to open stylist on them while they're in their sauna outfit it just brings them to their everyday outfit and no option to edit special outfits
also tried edit in cas same thing

Maybe someone will know how to edit the sauna outfit too, but another workaround would be to fix the CC hair itself. It's actually an oversight on the hair creator's part, from not changing the ID for the 'naked' hair when using those pigtails as their base. Unless EA actually set the pigtails as the hair of the sauna outfit for some reason.

Did this sim also get the pigtails when they bath or shower? If so, I can post the tutorial screenshots for how to fix it on the hair for you.