Yes, you can use ETHYL Acetate to smooth PLA in much the same manner as acetone will smooth ABS. However, ETHYL Acetate on PLA might not meet your requirement to hold maximum detail. ETHYL Acetate will eventually melt PLA. Nail polish removers contain acetyl acetate.
For smoothing, I've tried paint-on products like XTC 3D with variable results. It seems to be less work to paint a glaze on (vs. vapour) and with practice you can directly control how much detail you want to retain in complicated areas. However an absolute requirement for XTC 3D is a method of properly clamping your object so you