If at minute 10:24 you don't fall through the floor you had spam/mash A too slowly, so disactivate the stick then pick up the weapon, go up on the stick and try again (drop the equipped weapon, then spam/mash A as fast as you can, then press + while spam/mash A)
For methods 1 and 2 you have to drop the material, until you have 1-5 (depending on the method). If the cap for materials on the ground is 21, does that mean that you can only do up to 21?
I think you are trying it on a ledge that is too low (the higher it is the easier it's to do the glitch) i recommend the one you see in the video, however it is a matter of timing you have to be able to drop the material before you hit the ground or you are too far from the ground
