Well still, it would be close to an hour per group.
If it was 1 minute per person, it would be 25 minutes a group.
Which would mean, lets say the park is open 10 hours a day:
80 hours a day
4800 minutes a day
There is a 25 minute interval 192 times a day.
25 minutes = 25 people
Which means
4800 people could pass through and have a wand chosen every 1 minute
2400 people every 2 minutes
1600 people every 3 minutes
1200 people every 4 minutes
960 people every 5 minutes <---at this rate UO would only make $23,990 a day and that is IF the person choses to buy the wand.
I'm going for a 1 out of 25 will be chosen to pick a wand.
Regardless if they do one person at a time, or one per group, if the experience takes 5 minutes, only 960 a day will have a wand choose them, and at $24.99 UO is still making a pretty penny. And in a theme park with a capacity of 20 - 30,000 and 960 getting a wand, I doubt only 3% of all people in the park will be able to see the experience.
So 960 will get a wand, but 4800 will get to see it, still a very exclusive experience.