I recall the INITIAL DISCUSSION on the FML which led to the use of the
word "dook".  (I was in the "cluck" camp when we discussed descriptive
words way back then.)  The ORIGINAL PRONUNCIATION GIVEN IN THE THOSE
POSTS WAS "DUKE", not "duck, and not "doc".
 
(BTW, "Speedbump", "Carpet Sharks" and several other words and phrases
common in the ferret world began in the FML.)
 
On the other hand, pronunciations change over time.  For instance, the
name of the town where I had my K-9th year education, Setauket, was
always pronounced with soft vowels, a hint of "L" attached to the "U" by
those of us who were locals with many generations there behind us, but
the city (NYC) people who moved in in large numbers starting in about
1958 moved the accent in the word to the first syllable where it had
never resided before, made the first e into a strong E, and changed the
"tual" sound to "taw".  People whose families were there for hundreds of
years have found themselves "corrected" for decades by relative newbies.
So, that said, I'd bet that there are now regionalisms to the word "dook"
so that you will find different pronunciations in different areas.  (BTW,
given that one early spelling was "Settlecot" the chances are high that
we "old-timers" had our own changes from the way the town name once had
been said.)
 
So, you have the history, but my bet is that by now there are some
regional differences.
 
***** Hey, given the original pronunciation, is the ultimate ferret
talking song, "Duke of Earl"?   Everybody, try singing to your ferrets
and let us all know in a post what they do if it is interesting!  *****
[Posted in FML issue 4879]