It is probably something that he read on a different type of cleaner website or a different contractor's site where they are bashing cleaners to promote their own to make a buck.
I washed a brick/vinyl house for a new customer yesterday where he was told and read that bleach is bad for vinyl and he was concerned with using it on his house. I talked to him about it, explained that I have been washing vinyl houses with my soft washing system for a number of years along with my own house and not ever had a problem. We talked about the chemistry involved in the soaps and vinyl and other surfaces and put his mind at ease and explained about competitors or other cleaning chemical companies bashing certain chemicals to promote their own and he understood. We talked about other things and he agreed that soft washing is the better route to go after we talked about the competition and the other chemicals out there that are bashing bleach and what happens when you use those other products.
This new customer could not believe how clean his house came as we worked on it!
He was truly amazed and said it was like Magic!
He admitted that he was sceptical about what I told him and I told him that is ok, I understand as there are a lot of companies out there spreading a lot of b.s., over-hyping themselves and promising "miracle-like" results when you hire them and has seen some of their b.s. before and did not want to deal with those kind of companies.
When the job was done and we were rolling up hoses I asked the owner if he feels he received good value for his money he told me that he was definately happy, his wife is very happy and he will have me back every year or twice a year as needed and will tell all his neighbors. It is nice to have these kind of new customers.