If my goal is to feel good and take my time, I’ll generally go have sex with my wife.
Talk about a chore, why would I want to spend an entire 15 minutes or more of my day wanking?
Hey, I’m older. It takes me five minutes to remember how to do it.
Dennis
Yeah, why bother?
Flirt with yourself. Pull back from it. Play hard (ahem) to get. Stop before you’re finished and go do something ELSE for an hour, then come back and do the same until you can’t stand to interrupt it any more. Torment yourself, it’s fun!
It’s mostly that it was socially unacceptable to discuss in public. You could use a joke in a movie about a cold shower; masturbation, not so much. Same thing for cursing–people cursed all the time in 1930s but say “give a damn” in a movie and it’s a scandal.
But why would the cold shower or masturbation be necessary? Arousal will go away on its own in time, and usually a lot less time than it would take to be able to arrange for the privacy needed for either “solution”.
Has the OP never heard the old saying: There are no stupid masturbation questions.
Something’s bass-ackwards in this whole thread, that not one poster has remarked upon yet.
Cold baths (or showers) are (or once were?) widely thought to increase testosterone production and thus enhance sex drive and performance (in males anyway). Cold baths were prescribed to increase men’s libidos and treat erectile dysfunction. Among the benefits of cold baths or showers:
(Link in original.)
The James Bond Shower: A Shot of Cold Water for Health and Vitality
ISTM I’ve seen similar discussions in various of those men’s self-help type of books you can find at Barnes & Noble, or least that was popular 40-some years ago.
Years ago, my office got a lascivious photo in the mail.
Me: “Boy howdy! 'Scuse me, I’ll be in the bathroom for a half hour.”
Female Co-worker: “A HALF HOUR? Take ME in there with you.”
It takes me a good five minutes just to get consent.
ETA: I just realized, maybe some of you sick fucks don’t bother with consent. 
… Consent… to masturbate?
There’s no such thing as stupid masturbation.
Do you always call yourself afterwards? Do you still respect yourself in the morning?
These days, you could both sue each other and the company for that kind of exchange. PROFIT!
Finding a typewriter that can handle the multi-part consent forms is the difficult part nowadays.
Although filling them out while typing one-handed can be a challenge in and of itself.
What’s missing from this discussion is the physiological effect of cold showers, which is well researched.
Overview of effects of water at various temperatures (meta analysis):
Scientific Evidence-Based Effects of Hydrotherapy on Various Systems of the Body
Sounds like a variation of an old joke.
Professor in “Hygiene” class: “Is an hour of pleasure worth a lifetime of shame?”
Student: “How can you make it last an hour?”
I donno. He was a spectator and not a participant, which makes it a far less challenging, although equally as stupid.
I’ve done cold water immersion while kayaking and all I felt was miserably cold.
I also took ice cold showers for a month (I notified my utilities two months prior to moving. The gas company shut off my gas a month early, and I accepted the challenge). An ice cold shower really wakes you up. It’s uncomfortable, makes it difficult to breath, and leads to a very quick shower.
Don’t people just think about Baseball?