I thought Misogi was ritual purification through diving under waterfalls - I didn't realise it could be done in the way you describe. Sounds quite a good idea though. Most people wimp out of bokken cuts after about 400. Did you have an idea of how many you did in an hour and could you keep it up for an hour? ( I would guess about 3,500 if you can do one around every second).
Also, did it improve your bokken cutting or any aspect of technique or do you feel more positive in your aikido (psychologically?). Or maybe it made your bokken cutting worse?! I've often thought about doing an ocean Misogi where we dive in to the water off the coast here, but maybe this bokken cutting stuff would be a laugh as well.