Mmmm, interesting, never heard of that to alleviate front end looseness.
Me neither. It was an act of desperation. I had tried everything else that I could think to try; usually geometry and tire pressure were good enough. I tried way more than that; and still front-end push.
Your mileage may vary; maybe it was an issue specific to my 2009 YZ250F. I was running my rear wheel farther back in the adjusters on purpose. It turns out that was a bad idea; the exact opposite was fantastic.
I rode it again yesterday; the front end is sticking like glue. It's probably because I've done so many things... but finally, I can come into a flat corner, get off the gas, lean it over, and have it stick right there until I can get back on the gas and transfer the weight back.
One can argue that I shouldn't be "riding the front" like that into the corner... but it's nice to be able to. Before, it seemed like I had to be ready to catch the front end slide pulling stuff like that.