I know this is an old post, but I reckon it would make it stronger

These people reckon it does. not very good evidence I admit:
http://www.makeraser.com/smooth-and-...en-your-prints

It would depend how deeply the acetone can penetrate, especially if you have a complex multi layer object.

It would be an interesting experiement to see what force is required in a "shear" test to break laminated abs with and without acetone vapour treatment.

You know what would be cool An acetone nozzle. dribbles acetone on every layer of filament. not sure if that'd work at such high heat it'd probably just evaporate straight away.