Watching My Language (1997)
Bannard quote in book by William Safire, p. 272.
"Wean" means to take off the breast or bottle, but "weaned on," in my memory, at least, has always been used to indicate what was given as an inducement to accomplish the weaning. In the late '40s, in sixth grade, we read that Pecos Bill was so tough because he was "weaned on snake venom." I remember bad guys in the movies as having been "weaned on whiskey." The phrase, by its nature, has a meaning nearly opposite the word alone. It is useful and traditional, and I think it should be correct. Otherwise the bad guys would have to be "weaned away from milk by the substitution of whiskey." And that would never do.