I just had take off! It went about a foot, not super high, but it flew! It turned out that getting a good seal around the base was more important. I did get some leakage from the rocket and I'll fill those holes now I know where they are, but it flew, I really can't believe it! See updated instructions. Next time I'll use pure bicarb. Also, I think I might make the rocket more bulbous to get more fuel in it, and sealing with acetone to build up more pressure.