Ethanol is used in laboratories, this type of work generally needs a 100% perfectly clean finish, hence the use of ethanol.
Isopropyl alcohol is more readily available and less expensive than ethanol, for detailing work a 1:1 solution of IPA / distilled water usually provides sufficient paint surface cleaning.
Using 70% strength isopropyl alcohol in order to obtain a 1:1 ratio (50/50 % mixture) use 2 parts alcohol to 1 part distilled water (See relevant sections for usage and dilution used.) Mix solution in a spray bottle, spray onto clean paint surface, and wipe off with a micro fibre towel.