Haha cheers. They've all got a bit of a shuffle to them and some kind of movement. It's hard to work out though as there's always so much going on at the same time. Need to sneak into there studio and get the raw files to inspect
without listening all i can guess is velocity modulation maybe a heavy hat on a off beat (almost like a snare) and lighter ones in a shuffle motion to get a chikachika grove... then make a hipass filter sweep.
I had a look through a few F&G tracks and i think i hear what you're talking about. I found something like that in Just a Thought and it sounds like rimshots rising/lowering in pitch layered with a shaker over the kick in.