^^^ Agreed!
I actually have 7 Leopard Geckos (4 of which are my brothers), and every single one of them is different in how they "hunt/eat" their food. With the 2 of my Geckos that I've had the longest, all that I had to do was lower the pinkies with the tongs, and they just snatched it right away. But they're very alert, responsive, and quick to eat most moving prey. They are quite good at chasing down crickets, and almost never miss.
Some of the others are very different, as they won't just pluck the crickets or worms off of the tongs, but I have yet to offer them pinkies. I feed some of them primarily with tongs, as they don't have the same hunting prowess, so they're more likely to miss and accidentally get a mouthful of substrate. I believe their less than enthusiastic eating style would make them less likely to just snatch a prey item that's foreign to them, such as a pinkie.
So basically just try lowering the pinkie with the tongs, wiggle it if you have to, and see what happens. If that won't work, perhaps try placing some sort of tray/dish in the tank (as to not get substrate directly on the pinkie), then drag the pinkie across it to mimic a cricket running. Just some suggestions...