That video is ridiculous. Dig under wheel to level TT? Pack around a ton of cinder blocks and plywood squares? Place styrofoam on the ground first?
There is 3 dimensional movement involved in what occupants feel from inside. Fore/aft, vertical and lateral (side/side). There can be compound movement in more than one direction simultaneously similar to roll, pitch and yaw in a plane.
First line of attack is the fore/aft and X-chocks between the tires works very well. You should be using chocks anyway so no big deal to go to X-chocks.
THE most annoying component of bounce is vertical movement. Structural engineers spend a lot of time analyzing floor vibration and deflection in buildings to minimize the perception of movement and TT frames/floors are similar. Some TTs suffer more bounce than others and it depends on factors like the frame's strength, length and mass of the TT. Also, some subfloors have more deflection than others (depending on joist spacing and material used) which can add to the issue. Screw jacks or bottle jacks are the thing to use with one near each corner. An extra set of jacks near the axles can help in some cases. Some TTs have frames higher off the ground (ours is 24") and you'll need some sort of blocks to raise the jacks off the ground. Aluminum screw jacks only go to max. 17" high (min. 11").
Raising a jack to it's max. height makes it less stable in a lateral direction and you are better off building up the base of them. You could reduce lateral movement significantly by keeping the jack raised as little as possible and making the bottom of the blocks used to build up the jacks twice the height the top of jack is off the ground. For ex., if the top of the alum. stacker jack is 12" off the ground, the base would be 24x24". This is assuming the ground the base is on is flat and stable.
Lateral movement can pretty much be eliminated by using stabilizer braces like the BAL Lock Arm, UF Eliminator, JT's Strongarm or Steadyfast. With X-chocks, you won't really need ones in a fore/aft direction. A pair of BAL Lock Arms mounted side-side (in front and in rear) is cheaper and all that's really needed.
Some don't think that stabilizer braces are needed and don't do much and can be quite adamant about it. Each person's situation is different and some may find the braces help a lot while some may find that screw or bottle jacks are good enough and stop there. I find that with using the alum. stacker jacks, it's still not quite good enough. I have a set of the BAL braces I'll be installing soon.
For those that have elec. stab. jacks, they do a poor job of "stabilizing". To see how they fare, get down on the ground and watch what happens when someone walks up and down the entry steps. Manual scissor jacks work much better for controlling vertical movement.
