Scavenger hunts fall under hazing if only pledges are required to do them. Other than that, scavenger hunts often end up with people stealing items in order to win. Things have gotten out of hand.
For example, at my husband's fraternity, as a semi-joke one year, one item was "live nude girl." So one team went to a bar and paid a woman $50 to quickly strip at the house so they could get the 50 bonus points (most items were 5 or 10 points). I think that they discontinued the scavenger hunt after that, since they didn't want to end up in a, shall we say, compromising position.
As for pledge books, if it takes an hour to track down everyone for interviews and do the interviews, that's 23 hours worth of stuff that they have to do in addition to learning the fraternal history, STUDYING, eating, etc. Sometimes people are hard to get a hold of. My husband's fraternity used to do this (I don't think they do anymore), and it took a lot of time to track down some people. They had to get every member's interview.
Again, if it's something the entire fraternity does, that's one thing. But shouldn't your member be accepted because he's cool, passes the fraternal knowledge exam, has the grades, and wants to better himself, and not because he needs to take another 20 hours in six weeks to track people down to fill in their birthdays and majors?
Spend your 20 hours throwing some barbeques and game nights instead-- get to know each other because you want to.
