Yes, tiny water bowls will be much less wasteful of NB than larger bowls.
It usually takes somewhere around a week or so from the time the eyes clear up until they shed. I have seen it take as little as 4 days and as long as 10 or 12 days. Each snake is a little different.
Shedding tip - (not sure if somebody already mentioned this) - snakes are less likely to eat during the shed cycle. And if they do eat, they are more likely to regurge. So whenever you think the snake is about to shed, either skip feeding or offer a much smaller than usual meal.
Also - (especially for baby snakes and especially in winter or dry climates) - you might want to add some very damp (not dripping wet) moss or even paper towel in the warm hide once the snakes' eyes go blue until it sheds. It is more likely to shed quickly, easily, and in one piece if it has plenty of humidity at that time. And a damp hide is better than misting the whole cage, which often makes a wet mess, lol! Once the snake sheds, remove the moss and dry it for the next shed so it won't have a chance to grow a lot of mold and bacteria in it.