Another example of things that sound plausible but don't survive closer inspection is the just mentioned concept of a wad blowing a 'hole' in a pattern. Some feel the need to slow down or 'strip' the wad off the shot column at muzzle exit to prevent this.
Can't, never will, and hasn't happened. Acceleration stops at muzzle exit. The wad isn't pushing feathers, it's pushing Lead. Very quickly, the wad falls away from the back of the shot cluster. There is simply no force applied to the low density wad that can possibly cause it to interfere with the high density payload.
