Questions about Hob-e-Tac Accident or Removal

[Slyphic]

Long story short, how do you safely dissolve Hob-e-Tac (this stuff https://woodlandscenics.woodlandscenics.com/show/item/s195) from around the base of a fully painted and finished model?  Or is there a way to make it harden or fully set?

The full situation.

I was up later than I should have been last night, finished up a couple figures I wanted to base today, and decided to apply paste, swish through sand, cover in paste, and let them sit over night.

Turns out, I mixed up scenic cement and hob-e-tac, due mostly to sleepiness, but also an unlabeled bottle (I know, I'm fixing that as well). 

The base is still tacky, as expected, but it doesn't feel solid enough, meaning I can push the material with my finger and it moves, to just straight paint over. 

I've not been able to find ANY good resources searching around for how to remove the stuff, or if there's something you can apply to it to make it full harden, or whether you can apply something over the top and carry on.

I've got a goodly supply of solvents and cleaners, but I've never before had to spot-clean around a finished model.  These are 1980s Grenadier models, with thick integral bases, so I'm worried anything with low viscosity is going to interact with the lower parts of the painted figure.

I'd apprecaite any advice.  I've got three figures, and am willing to test different methods if there isn't a consensus.