Chinese water torture

[EdZotti at AOL.COM]

I'm researching the expression "Chinese water torture" for a newspaper
column. I have found some discussion of "Chinese fire drill" on ADS-L and
also at http://www.word-detective.com/back-x.html#chinese. Morris quotes Hugh
Rawson as saying,

<<"the use of the modifier "Chinese" in the derogatory sense of "confused,
disorganized or inferior" dates back to the time of World War I and was
largely a British invention. Other "Chinese" slurs of the day included
"Chinese ace" (an inept aviator), "Chinese national anthem" (an explosion)
and "Chinese puzzle" (one with no solution)."Chinese fire drill" seems to be
one of the few (fortunately) of these phrases that have survived in popular
usage. >>

However, nothing about "Chinese water torture" (which of course does not have
the implication of confused, disorganized or inferior). I have asked several
native Chinese speakers and "Chinese water torture" is unknown to them. So I
put the question before the house. Does anyone have any knowledge of the
origin of this term, or for that matter of the practice called by that name,
that is, torture by having water dripped on you slowly?

Thanks. -Ed