To keep the surface moist with acetone, put a layer or two of paper towels or a J-cloth on the bed, then soak that with acetone. To keep the fumes down and extended the time it takes to dry, and thus dissolve the ABS you can place a piece of glass on top, or you could use anything that is not porous or dissolves in acetone.
If you can find some pure methylene chloride, it will dissolve ABS very quickly, but it evaporates quickly, and I’m guessing it’s pretty toxic…
@Ryan_Carlyle Oh, I know. I only print ABS on my enclosed HercuLien printer. With the bed at 100-110C the encloser hits a nice stable 55C if I give it time to acclimate. But even with an enclosure at 55C, a clean PEI bed I can get curling at corners. So I use the disks as a helper… since I hate cleaning up the entire bottom edge from a brim.
@Chris_Setla_kaptain That may be the solution, after removing the bed and performing the process outside or in the garage.
@Ryan_Carlyle don’t tell my printer! I’ve only had one print split from not having an enclosure. Most of the ABS prints stick down well enough, it’s just the large footprint parts that I’ve had issues with. No doubt enclosed is a better option (and I plan to enclose it in the future) but for now I’m ok doing my smaller parts this way. On the larger stuff, I’ll just pull the juice out 
…and after you try all that, try some ethanol and water, with a twist of lemon, or an olive.
Upside down can of air and freeze it off, abs will flake off. I use that trick often to get things off the bed.
Will that hurt the PEI?
@Ryan_Carlyle I figured as much… I tend to play with things I have no idea about!
Actually, I ran into that stuff a long time ago when I was working a lot with ABS motorcycle parts and got some help from a local plastics company.
Acetone is probably bad enough.
Seeing this nearly made me cry. I have some 0.5mm PrintBite for the Prusa machines in the pipeline. The thinner surface provides a little more clearance to the bed probe whilst being able to provide the self release performance as the bed cools off. Some samples being sent out and will report back.