So I called all our no thanks candidates. The results of this gesture (intended to be cruel but kind, altruism in its most affronting form) have been mixed.
One candidate, who had been a clear "no" for us at the MLA interview, was so charming and collegial on the phone, insisting that s/he (anonymity must prevail or I will get myself sued) had "no hard feelings" and suggesting a grant my college ought to apply for, that I got off the phone feeling especially remorseful and wretched.
Another was so immensely peeved when I told her/him that s/he was 4th on our list, that we were in the short term planning to interview the top three, but that one never knew how things would go and there was a small chance we'd contact her/him later in the process, that s/he sent a snippy email withdrawing from our search altogether.
It's a mixed bag, trying to do this right. I lose sleep over it. I've been on the other end too often.