We do ours in water and then add milk at serving time because I like mine runny and Hardi likes his um, worse than lumpy. :~) But are you saying that you can crockpot it right in the milk?
We start with hot tap water but not boiled water, and it comes out fine even with the regular (not 1-minute) oats. But then since we have no kids in the house, or tap water is pretty hot.
We'll probably corck more often than not this year because I can start that on the way out the door to the day's pool workout, which afterwards I don't usually feel like standing around at the counter and cutting stuff up.