Option 1: Wave Maker & Anchor Person
The Wave Maker holds the ends of the tubes securely and starts to spring the length of both tubes simultaneously - just like the Inertia Wave method. The method of Thunder Slap is a spring-like up-and-down pattern whereas the speed builds, the tubes slap together on the ground like a crack of thunder. Keep the slap, keep the momentum.
Meanwhile, the Anchor Person holds the ends of the tubes on the opposite side and attempts to hold them in place.
Option 2: Wave Maker & Wave Maker
Both users are Wave Makers and simultaneously perform the Thunder Slap method as described above. Timing and communication are key.