I'm with you, Tom. I thought about responding to this and saying that I can't imagine ever wanting to hold my bow at full draw for 10 seconds, but then I thought, who am I to question something Byron Ferguson said?
I think that if a person can draw their bow and hold at full draw for whatever amount of time their shooting style calls for, without shaking, and repeat that enough times to get in a good practice session, that should be fine.