Just stop replying after you tell the candidates their deficiencies wrt the position. It's not that much different than what companies do now where they stop replying immediately after the interview. Even if the candidates are in denial and argumentative at first, they will have time to reflect on a specific issue. If 9/10 employers tell you that your breath is terrible, maybe it's time to investigate your morning bathroom routine regardless of how perfected you think it is now.
Minimal upside, lots of downside. Most hiring managers (reasonably) are vigilant about avoiding post-interview drama, which is what this is an invitation for.
I understand. During my job search I was getting pretty frustrated at the little feedback I received during the interview process. Some interviews were more qualitative "we want to watch your coding process" where there was no feedback from the interviewers and a stone wall from the company after the interview, which lead me to question whether or not I actually knew the skills on my resume as well as I had represented them. (As a fresh college grad, I didn't, but it wasn't obvious at the time.)
