I wonder if there is a similar tool with less depends. thanks for giving it a shot though. I did figure out a way to purge old config stuff with dpkg that works well. I doesn't help at all with orphaned packages.

# dpkg --purge $(dpkg --list | grep ^rc | awk '{ print $2; }')

works well for cleaning out all the left over configs, and is faster than doing a --purge 1 package at a time.