Downshifting to 2nd. as you roll up to a stop and shifting back to 1st. as soon as the vehicle quits rolling will also let you get ahead of the cluster gear spinning situation that's causing the problem. Letting the clutch out in neutral, getting all the gears spun up, and then trying to shift into 1st. is what's causing the grind. If you don't spend any time in neutral, there's never an opportunity to get the cluster gear spinning.
I love automatic transmissions- - - -they're smarter than all drivers, and most mechanics!
Jerry