Here's a poopy example of practicality:
In the first clip I use 3 rockets and a grenade. And the rocket I killed the spy with was basicly point blank so I took damage from that as well. You could do a lot more with 3 rockets and a grenade. And with better form you could do what I did with less, and probly look a lot smoother.
And the second clip while not at all "practical", I thought was neato. Two yellows on the ground, a blue in the air. But both clips are well within the reach of stock game play with no need to alter anything. Just an example of how not only can you do a lot with stock knock back, but that it can also be applied practically at least to rocket jumping