I would use a blade to clean the little extras off before the acetone bath. The bath will smooth some but when you have a lot of extra material it will not remove it all.
Is there a reason you are using ABS? It is not my favorite material to work with, especially not as a beginner. If you are wanting material as strong and resistant as ABS but 100X easier to print check out www.3dfuel.com and look at their APLA. (Advanced PLA) It has all the qualities of ABS but prints as easy as PLA, it is amazing material.