Since then I've come across a copy of an email Santer sent in July 1996 to the leading authors of the 2AR WG1 and all contributors to his chapter (8), a month or so after his ordeal began unfolding.
His words on the accusations of "scientific cleansing" give an insight into how that term was taken by him and others, and the context of the term at the time:
"You will all have received (from Dr. S. Fred Singer) copies of Dr. Singer’s letter of July 25th to the Wall Street Journal. This letter makes some very serious allegations, and again raises the spectre of “scientific cleansing” of Chapter 8. I am disturbed by the use of this term. Over the last few years, “ethnic cleansing” has taken on vivid meaning for most of us. We have seen examples of “ethnic cleansing” in Bosnia and Rwanda. “Ethnic cleansing” is a synonym for genocide – the systematic and planned extermination of an entire national, racial, political, or ethnic group. Singer’s allegations of “scientific cleansing” are morally repugnant to me, playing as they do on our familiarity with the use of the word “cleansing” in a non-scientific context."It's worth reading the whole thing. Santer notes that "Singer states that there is “an absence of any evidence for a current warming trend," a false claim then and one he repeated at his 2011 symposium at Portland State University.
Near the end of the email, Santer writes "Singer’s charges of “scientific cleansing” are odious in the extreme," and that
"No matter how loudly Dr. S. Fred Singer broadcasts his visions of political tampering and scientific cleansing, he cannot halt the inexorable progress of the science itself."Santer was certainly right about that, and Fred Singer was wrong.