I finally started scavenging MS DNS.

I have a guest wifi network with a login portal. Every portable device that comes into the area connects but does not login. They pull a IP address and a dynamic DNS record is created. Whenever I work on the DNS server, I am overwhelmed by all the useless records.

Here are a few stats on my zone.

1459 records
234 iPhones
32 iPads
36 iPods
140 droids

So I looked into scavenging and enabled it one of the DNS servers. I found 2501 in the event log.

The DNS server has completed a scavenging cycle:
Visited Zones     = 14,
Visited Nodes     = 2536,
Scavenged Nodes   = 1923,
Scavenged Records = 3556.
This cycle took 5 seconds.
The next scavenging cycle is scheduled to run in 168 hours. 

Now my zone now has 294 records and no mobile devices at the moment.