1. Acetone will eat most plastics and synthetic rubbers. I know, I use to work at a plastics factory and one of the tests we use to perform on our plastic was to soak it in acetone to see how the plastic broke down over time ("how" it broke down was very important to QC.) Most seals in your fuel system are made of synthetic rubbers like around your fuel pump and sending unit in your tank, any rubber fuel lines and your seals around you injectors. And lets not even mention that most of the injector's body is made of plastic!.
2. One cars with O2 sensors this is also a very bad idea. For one because the acetone may cause your O2 sensor to send an inaccurate signal to the ECM which can either hurt fuel economy or increase emissions (or both). And second, the O2 sensor is very sensitive to contamination. Once an O2 sensor is contaminated, it stops working all together and the only thing you can do is replace the O2 sensor. This is why they have "street legal" and "off road only" octane boosters. The street legal booster won't contaminate the O2 sensor where the off road only WILL contaminate the O2 sensor!
This is a very bad idea and NO ONE should try it. If you do don't say you weren't warned!