I had a reader ask me what Homer Kelley meant by the 'downswing waggle.' Here's a video by UK TGM instructor Simon Williams showing the 'downswing waggle.'
That's really all it is. As Homer described it (and quoted from Simon on his YouTube) it's 'a verification of alignments, a careful nursing of clubhead lag and a checkpoint for the flying wedges.'
So may ask what's the difference between this and the 'pump drill?' (Note: Just ignore her comments on what causes initial ball flight direction and what causes ball curvarture as the are incorrect).
The pump drill is more of a careful study of the alignments of the clubhead, clubshaft and the hands. However, it doesn't carefully focus on 'nursing' clubhead lag pressure nor does it usually check out the alignment of the clubface either. IMO, this game is about who can control their clubface the most consistently throughout a round with every club in their bag, especially the putter. So that's why I think the pump drill is a good drill, I prefer Homer's 'downswing waggle.'
One of the many things TGM helped me with is treating my time on the range like a scientist may treat his time in the laboratory. So there's a lot of experimentation, observation and feedback. Remember what Homer loved to say about verifying alignments...'look, LOOK, LOOK.'