Ethyl alcohol from 92 to 99% is the best option, however in some countries it is not permitted to use, or it is very costly and difficult of find. Approximately 38 liters of alcohol is used in the I Trouble 8.
In cases were the use of Glycol Propylene is necessary, the solution should be of 40% of water + 60% Propylene Glycol, totalling up approximately 38 liters of the mixture.
The brine is not more utilized, as it can provoke corrosive mischief to the equipment, and also deteriorates the environment.