Just to clarify and have it official, it appears that slingshotting (using tethered objects to make a makeshift slingshot) is classified glitchless, but it doesn't appear on the list of techniques used in game. It would be nice to have it on the list just for officiation.

Also, I assume that combining slingshotting and vehicle throwing (slingshotting a vehicle while you're in it) would also be glitchless since they're both considered glitchless, right?