“How to make holy water—boil the hell out of it”

An old joke is still told about how to make holy water:
 
Q: How do you make holy water?
A: You boil the hell out of it!
 
The joke has been cited in print since at least 1942. It’s not known who said it first.
 
   
Google Books
Proceedings of the annual meeting of the American Warehousemen’s Association
Volume 51
1942
Pg. 202:
At a recent luncheon Walter Massey poised the question “how does one make holy water”, and assured us that the correct answer was “boil the hell out of it”.
 
HathiTrust Digital Library
When Saints Go Marching:
The Memoirs of a Baptist Evangelist
BY Ethel Ruff
New York, NY: Exposition Press Inc.
1957
Pg. 143:
In the same church, the subject of “holy water” came up for discussion among the moppets.
 
“What makes water holy?” one wanted to know.
 
The other had the answer, which he delivered in all seriousness; “My daddy says, ‘You take plain water, put it on the stove, and boil the hell out of it.’”
 
Google Books
Old Hilarity
By A. J. G. Priest
Charlottesville, VA: Michie Co.
1965
Pg. 99:
“But, Bishop, how do you make holy water?” “Quite simple to the initiated. You take plain tap-water, just plain, ordinary tap-water. And then you boil the Hell out of it!”
 
3 November 1967, Amarillo (TX) Globe-Times, ‘Turnstile” by Thomas Thompson, pg. 2, col. 1:
Roy Bourland had lunch in Amarillo the other day, and he was talking about his recent trip to some of the outer Hawaiian islands. One of these chatty-type pilots was at the controls and he pointed down to a building and said, “You see that building? Holy water is made there.”
 
It was one of those cliffhanger observations, and finally a woman passenger asked, “How do you make Holy Water?” The pilot answered, “You boil the hell out of it.”
 
11 May 1981, Philadelphia (PA) Inquirer, “Americana,” pg. B1:
You know how to make holy water? Put the pot on the stove and boil the hell out of it.
 
Google Books
What’s so funny about being Catholic?:
An uproarious collection of blasphemous facts, unholy jokes, irreverent folklore, and more
By Karen Warner
New York, NY: HarperPerennial
1994
Pg. 144:
How do you make holy water? Take a pan of water and boil the hell out of it!
 
Google Books
All Kinds of Humor:
Jokes, Quips, and Fun Stuff for Many Occasions ..., Book 2
By Frank Verano
Xlibris Corporation (Xlibris.com)
2012
Pg. 207:
How do you make holy water? Boil the hell out of it!