You are correct in that rebounding is vastly superior to any other form of excercise when it comes to pumping lymph. The advantages don't stop there though. You can exude high G forces in a smooth motion that would smash your joints if you tried to do it without the trampoline. It is estimated that you go from about 3 G's at the bottom of the bounce to 0 G's at the top of the bounce. Now think that you can do this hundreds of times whith minimal streess on the joints and you can begin to understand the benefits. This creates a superior pumping motion. You can do this effortlessly on a trampoline for long periods of time. It is unequivically the best lymph drainage excercise there is. This is agreed on by most healers.
Here are some links explaining the numerous benefits of utilizing a mini trampoline. I have studied and utilized hundreds of healing modlaities over the years and I include my mini trampoline as one of the very best physical healing modlaities there is.