The humane thing to do, is get a second one, and then race them across the tub, before washing them. Must tire them out. Then you tell it what you are going to do to them. once the water is boiling, you hold it over the steam, to let it know what is going to happen, before placing it in. Let the second one watch. The tell it, the same is going to happen, and then dunk that one in. Cover, and wait.
In truth, though, the humane thing to do is wash and then toss em into the lobster boiler (the large pot), without killing them, and chopping them. Plus, they taste better that way, and you are not losing any of the flavor.