RE: for those who still use butyrate dope
I'd recommend you stay with the ketones (Acetone, MEK (Methyl-Ethyl Ketone), etc.) and organics as well. Alcohol is a water-based or at least water-loving substance and something about the idea of mixing water into dope leaves me a feeling uncomfortable.
About solvents like Acetone etc... you're likely to find that hotter solvents (i.e. the ones with lower flash point/faster evaporation like acetone vs. MEK) produce more shrinkage, give you less working time, and are more likely to blush. (Whether that's bad or good is situational... if you're tightening up the silk you just applied to a strong airframe that may be great... if you're looking for a perfect finish on a lightweight scale job, it could be disastrous.)
BTW, if you don't know what flash point means, find out before you use any of this stuff.