How to dissolve PLA (polylactic acid)?
Ethyl acetate disolves PLA - which is typically the ingredient in non-acetone nail polish removers.

https://en.wikipedia.org/wiki/Ethyl_acetate

According to Wikipedia:


  "If the filament is soaked in a small amount of ethyl acetate, it will dissolve and can be used to clean 3D printing extruder heads or remove PLA supports. The boiling point of ethyl acetate is low enough to also smooth PLA in a vapor chamber, similar to ABS and acetone."