Just bought a house that needs washed. I just bought a Ridgid washer as suggested by multiple people. Do you guys mix up your own (dish soap, bleach, etc) - if so what ratio's? Or Do you buy a soft washing chem from somewhere? If so, can you get it from a big box store. I'm not really looking to mail order something for a once a year job. I'm also looking to low pressure do the roof. Again, suggestions on getting chemicals. Reading through most of these posts is pretty cryptic. Thanks in advance.