UPDATE 2014-03-21
So I realized I wasn\'t as efficient as I could be, as all the disks that I needed to \"scrub\" were under /media and
You don't need to escape DOT in shell glob as this is not regex. So use .AppleDouble instead of \.AppleDouble:
find $DIRTY_DIR -name .AppleDouble -exec rm -rf '{}' \;
PS: I don't see anywhere $COUNTER being incremented in your script.
tl;dr - Pass -prune if you're deleting directories using find.
For anyone else who stumbles on this question. Running an example like this
find /media/disk3 -type d -name .AppleDouble -exec rm -rf {} \;
results in an error like
rm: cannot remove 'non_existent_directory': No such file or directory
When finding and deleting directories with find, you'll often encounter this error because find stores the directory to process subdirectories, then deletes it with exec, then tries to traverse the subdirectories which no longer exist.
You can either pass -maxdepth 0 or -prune to prevent this issue. Like so:
find /media/disk3 -type d -name .AppleDouble -prune -exec rm -rf {} \;
Now it deletes the directories without any errors. Hurray! :)