I've done a lot of kettlebell windmills in the past, but these days I only regularly do Dan John's version with a stick (I use a PVC pipe). You can do this with a narrower stance or a wider stance, and you play around with the balance of weight between the front and back leg.
Brett's article specifies a narrow stance, keeping 70% of your weight on the back leg, and keeping the back hip lifted. I usually use this as a starting point, but I also move around in the bottom position, softening and straightening the back leg and shifting my weight back and forth between my feet, finding room to get deeper into the hinge, more like you would in a bent press. So keeping the weight on the back leg is just one position that I explore, not a strict rule to follow.
With the stick I also explore different positions of holding the stick, varying my grip with, how low I have the stick on or behind my shoulders, and whether I am pushing my elbows forward, which helps to open up my chest and shoulders. While I'm at it with the stick I usually also do some dislocates and few other stretches with the stick. There's a ton of stuff you can do with a stick, and there are even companies that sell special mobility sticks.
I sometimes do stuff like this as a warmup, sometimes as separate mobility work, and sometimes as a quick break from sitting and working at a desk.
Here's Dan John's demo with the stick:
Here's a video of a related rotational move they call the "slap shot" from a company that sells mobility sticks and has lots of videos with different moves:
