In this demonstratioon, you dip a piece of paer into some ethanol and burn it.
You then can claim to be feeling lucky and are going to try it with a £5 note. This time you dip it into a 50:50 mix of ethanol and water.The water in the alcohol-water mixture evaporates and keeps the temperature below the ignition temperature of paper (approximately 230 °C. The paper will still be wet with water after the alcohol has burned away. Sodium chloride gives the flame the characteristic orange colour of sodium, which looks like a normal yellow flame.
Don’t get too excited. I know of one person who used a £20 note off his supervisor and, got confused and ended up dipping it on the wrong ethanol, reducing it to ashes.