I brushed on the soy gel and left it on for almost two hours and then wiped it off with scratchy pads. It really didn't penetrate the deep layers of paint but did a great job on the top latex layers and the paint residue in the grain of the wood...and now I'm feeling doubly stupid for the mess up yesterday.
I should have tried the soy gel first. I actually had the soy gel—I just needed to go dig around in the basement and find it. So now it looks like we'll actually be able to get quite a lot done this winter without being able to open up for ventilation.
Now I just need to go get some oxalic acid and borax and try and lighten up that panel I darkened yesterday. Hopefully that will work.
I'm rather hoping we can get a good first pass done on the walls this winter. Then, next spring, when we can open up the windows again, we can use the removers that require good ventilation.