Go to Wal-Mart or Walgreens. Go to the cosmetics section, "100% Pure
Acetone" is used as nail polish remover, in 16oz bottles for around $3. I
take them and put 4 marks on the bottle evenly spaced, for 5 delineated
sections of just over 3oz each, perfect for my 15gal tank in my vanagons.

I buy it by the gallon also and refill the plastic bottles for more
economical purchasing, but even at $3/16oz it's not going to break you;
that's enough for 5 tanks of fuel. Spending $3 saves me around $40.

The acetone does what's advertised, it's not snake oil.

John