We just bought a portable dishwasher, and the sink has a single handle faucet with a sprayer (side spray.) (This video https://www.youtube.com/watch?v=yTlmbpje7Js shows what the connection looks like. The dishwasher connects to the end of the faucet much like this https://www.youtube.com/watch?v=fszaXdH5K64)
The instructions for the dishwasher (and other brands) say to remove the side spray because the hose isn't designed for the constant pressure like when used with the dishwasher and is likely to leak. That sounds plausible, but isn't the diverter the thing taking the pressure? And if that's the case, how does removing the side spray prevent problems?
EDIT: Added details of the hose connection.
Best Answer
Side sprayers or vegetable sprayers are a known weak point of most faucet designs. The valve is not meant for long-term pressure and are not designed for that task.
The diverter valve does play a role, but it's not to cut off water flow from the sprayer. The diverter's job is to cut off water from the main faucet and divert it to the sprayer when the pressure on the spray side drops (when you pull the trigger).
Normally, most of the water pressure is going out the faucet and the sprayer only has to stop a small fraction of the pressure. When a dishwasher is hooked up to the end of the faucet and the water flow is stopped, the sprayer then has to deal with the full pressure of your water system.
To remove the side spray, you will need a threaded cap to cover the connection on the faucet where the spray hose connects. You can remove the sprayer and take it to the store to ensure you get the right size. This should be reversible, so if the dishwasher is no longer used the sprayer can be reattached.