Do any sororities COB?

Only house I’ve seen have a link in their bio is sigma kappa, but the link was shut down bc no one wants them lol

Yes, houses do COB but you need to realize that it's not a secondary rush and a back door because you don't like the idea of formal recruitment. Not every house does it, and the girls who get COB's are the ones that sorority members already know, either through having gone through recruitment and ending up dropping, or making friends with members in dorms or class or friends of friends. And the top recruiting houses don't offer many COB's at all and they are REALLY hard to get so you would need to keep that in mind. Your best chance to meet members and get an idea of where you could fit is formal recruitment, whether you see it through or not. And as a member you are going to have to deal with recruitment on the other side, which is not any easier I promise, so there's no avoiding it one way or another.

the houses are on the panhellenic site every semester and right now it's

Alpha Delta Pi
Alpha Phi
Kappa Alpha Theta
Sigma Kappa