Dyeing Windsor and Newton causing doll to resist dye?

I wasn’t happy with my faceups for my dyed Oswin and wiped him twice with Windsor and Newton brush cleaner as Lomi’s Playground demonstrated that it could remove MSC without affecting the dye. I gave up trying to work around some patches of uneven dye and completely removed the dye with a wipe of rubbing alcohol and used the same recipe, but this time two things have happened:

1. He’s taking an insanely long time to dye: I’ve had his head in the dye for nearly two hours and he’s only starting to approach the tan I initially got after 1 minute.

2. He has completely undyed patches on the parts of his face up that were darkest/required most effort to remove (eyebrows mostly). I’ve sanded them pretty roughly with 200 grit sandpaper and it’s done absolutely nothing to help them take the dye.

I’m at a complete loss for what to do or what on earth happened. It’s behaving as if there’s oily residue on those areas but I already washed the head beforehand with soap and Magic Eraser and the sanding being useless makes me afraid that the W&N has somehow ruined the entire piece of resin.

I really don’t want to resort to airbrushing as I’ve never heard of someone doing that successfully with resin-safe paints.

 

Update: I just gave up and painted his head with acrylics. Won't solve the issue of faceups taking off the tan underneath but acrylics are super easy to remove and much faster to re-apply than dye. I think I got a reasonably close color match here (body's been blushed so it looks much rosier)



There's no precise measuring with paint, but in order of most to least quantities I mixed:

White
Raw Sienna
Burnt Umber
Vermillion