Sorry, OP. But I'm a little familiar with the UW greek system since I live in Washington and know many girls there. Luckily, UW keeps an updated list of chapters participating in COB
http://www.uwpanhellenic.com/join/cob.php
12 chapters are doing it according to the list and you can register for COB. Also, before COB begins, you should reflect on recruitment week and think about how things went.
-How were my grades?
-Did I have recs?
-Were my conversations good?
-Did I seem interested?
-Did I have any connections with girls I knew in houses?
-Did I show actual interest?
-Was I quiet/shy?
-Was I too loud?
Those are all things to think about/work on until you do informal. Best of luck!