i use the boost juice from snow performance. Shipping for it is free from summit, and it lasts awhile so buying a case of four isnt too bad. I wouldnt trust wiper fluid, as its not consistent in its alcohol %
really depends on what kit your running, you can run straight meth in most kits aslong as it doesnt sit for a prolonged period of time. if your running the alkeycontrol kit your good to run straight all day an it can sit