Multi-container pressure washer and related product selecting valve

A method for washing out a pressure washer that includes a single pump fluidly connected to a primary water source, a mixing device that is fluidly connected to the pump, a valve having a device conduit fluidly connected to the mixing device, first and second containers having respective first and second chemical products therein, a first conduit fluidly connecting the first container to the valve, and a second conduit fluidly connecting the second container to the valve, the method comprising:

• providing a wash out assembly including a third container having water and a third conduit fluidly connecting the third container to the valve;
• adjusting the valve to direct the first chemical product from the first container, through the first conduit, valve, and device conduit, and into the mixing device;
• adjusting the valve to direct water from the wash out assembly, through the valve and device conduit, and into the mixing device to wash out the first chemical product from the valve and the device conduit;
• adjusting the valve to direct the second chemical product from the second container, through the second conduit, valve, and device conduit, and into the mixing device;
• pumping water from the primary water source;
• and
• mixing the second chemical product with the water from the primary water source within the mixing device.