Is Barry claiming that you only need a water based cleaner? If so, he is very wrong. You need to be using a true wax and grease remover AND a water based product (a water based product will NOT remove wax or grease and a W&G remover will NOT remove a water born contaminant) Sprayway glass cleaner will cover your needs as far as a water based cleaner and it only costs about $2 a can. Some of this crap the paint companies are trying to sell to the public is a joke. I was a Sikkens paint rep. for 2 years. During that time they tried to get us to push a water based cleaner at $50 a gallon But, They also stressed the fact that you also needed to use a regular W&G remover.