In 1970’s we took a standard Western Electric/ Bell System office phone at work and modified it. Removed speaker element @ screwed cap back on over a Saran Wrap seal. Then inverted the handset long enough to carefully pour in water thru other end with mouthpiece inverted with element removed. Then carefully returned handset to cradle after screwing carbon element mouthpiece cover back on. It was on the office heads desk- a guy who was s always playing jokes on others.
Next with all of us in the room we watched him sit down and we dialed his phone. He picks up the handset and water pours out of the holes in mouthpiece cover and goes all over his shirt ! I couldn’t stop laughing for days !
He even laughed .