Dry clean I understand what you are saying but if you worked on the coast doing large hotels lagged in salt every six weeks you would soon change your mind , one job that we do used to take 3 full days with cold water , with hot it takes a day and a half as the hot water dissolves the salt so much quicker and the windows dry much faster making the customer more happy as there guests don't like wet windows !!! lol I certainly wouldn't want to go back to cold although it will do the same job but slower , I do admit it's expensive to run on diesel however that's offset by the fact that you can get more work done in less time , I know that sounds a bit like an Ionic's advert but we have found it to be true . Also being by the coast we get a lot of baked on seagull poo this is difficult to get off with hotvand virtually impossible with cold , if you are doing 4 weekly maintenance cleans it is less important to have hot but still makes you quicker and if you pick up a new job makes it far easier ,.