In my understanding, however, the laser pointer test involves actually photographing the laser point on the wall, not just viewing it with your eyes. Therefore, the test should work just fine to tell you if the slap is affecting the camera during exposure.
As for the penny test, it is just silly, IMO.
I've usually heard the laser test as attaching the pointer to the camera and watching the spot dance. I think photographing the spot might tell you something, but a photograph of a projected laser spot wouldn't be as informative as a photograph of a resolution target with and without mirror lock up, if one were trying to determine the effect of mirror slap.