Broadway columnist Walter Winchell (1897-1972) used the term “Wyoming ketchup” for “liquor.” The term was not explained, but perhaps Winchell felt that liquor was a mere condiment in the Wild West of Wyoming cowboys.
 
“Wyoming Ketchup” was cited in a Winchell column of April 26, 1930.  Winchell first used “Ketchup” (uppercase) and then, later, “ketchup” (lowercase).
 
 
Wikipedia: Walter Winchell
Walter Winchell (April 7, 1897 – February 20, 1972) was an American newspaper and radio gossip commentator.
       
26 April 1930, Wisconsin State Journal (Madison, WI), “On Broadway” by Walter Winchell, pg. 3, col. 6:
The gayest of the Heartache Square asylums is the Abbey on 54th street just this side of the canyon. It is where the night loafers pause with their magdalens before going home to their wives, after they have filled themselves elsewhere with Wyoming Ketchup.
 
22 May 1930, Wisconsin State Journal (Madison, WI), ‘On Broadway” by Walter WInchell, pg. 3, col. 6:
Between specialties “Gypsy” was urged by the management to be sociable and sit with some male patrons—the sort who hare to get cooked up on Wyoming Ketchup so that the listener will check their banal comments to “stew stuff.”
 
17 October 1930, Evansville (IN) Courier, “Walter Winchell On Broadway,” pg. 10, col. 3:
Yolanda (Club Callas ) Lossee will appeal for an annulment, pleading she was full of Wyoming Ketchup when she married him.
 
23 February 1932, Richmond (VA) Times-Dispatch, “Walter Winchell On Broadway,” pg. 7, col. 5:
Things I Never Noodle Now.
(...)
That if you consume one-half pound of butter before going gay on Wyoming ketchup you can drink an elephant under a carpet.
 
Google News Archive
12 January 1944, The Times (St. Petersburg, FL), ‘Walter Winchell On Broadway,” pg. 14, col. 6:
There’ll soon be a swing to intimate night spots. Acts want too much dough and Wyoming ketchup is getting scarcer.
 
Google News Archive
9 October 1944, S. Petersburg (FL) Times, “Walter Winchell On Broadway,”  pg. 16, col. 5:   
But even with the help of Aphrodite, the Goddess of Love (he should have tried Wyoming ketchup), he failed and had to drag her off to Troy by force.
 
Google News Archive
1 July 1960, Sarasota (FL) Journal, “Broadway Beat” with Walter Winchell, pg. 12, col. 5:
because he’s a nice guy and we footnoted that it was stew stuff meaning too much Giggle Water or Wyoming Ketchup.
 
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20 May 1968, Spartanburg (SC) Herald, “Big Names Get Around” by Walter Winchell, pg. 4, col. 5:
He also was floating on Wyoming ketchup—one of the happiest drunks we ever saw.
 
Google Books
Winchell Exclusive:
“Things that happened to me—and me to them”
By Walter Winchell
Englewood Cliffs: Prentice-Hall
1975
Pg 279:
One mad midnight {the story goes) he was very upset about Marilyn being so sick from too much Laughing Soup and Wyoming Ketchup.