I just take the hose off the impeller housing. Then i have a old car heater hose that slips onto the housing. On the other end is a plastic hose adapter that you can find at any hardware store.
Takes only a couple minutes. I used to use a toilet plunger but it never sealed well.
You cannot run high rpm for long though on land, regardless of any system you use. You cant supply enough water and youll fry the impeller.
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Another spot to do basically the same as above but easier to reach is removing the hose from the intake side transmission cooler. At least it's easier on the older boats.