Way back in the 1990s I started doing only cold showers in the hope of reducing the number of days I felt sick.
At the time I worked at a company that had a full medical department: a doctor and a couple of nurses. One day I went there for some reason or other and the doctor looked in my ears and said that they were all jammed full of "wax." He then spent a long time irrigating them.
I had never had an ear wax problem previously, so I attributed it to the cold showers. I figured that when I took long hot showers, enough hot water got in to keep them clean.
Some time after that I stopped the cold showers.
Fast forward a decade or so. I have been doing the cold shower thing now for the past three or four years. From the beginning I have been fastidiously keeping my ears clean. This is what I do:
1. Every other week I lie on my side and put olive oil in my ear with a medicine dropper. I try to keep it in at least 15 minutes in each ear before draining it.
2. The alternate week I use a soft vinyl bulb called an ear syringe and squirt warm water into each ear. I follow the instructions that come with it. You do not want to direct a strong water stream directly against the ear drum.
I have no problems now with ear wax. You can find just about anything on the web but I don't think anyone else out there has mentioned the connection between cold showers and wax-filled ears. I'd be curious to hear if there are other similar experiences.
I know that our evolutionary ancestors lacked medicine droppers and ear syringes. I further know that if I were truly an experimentalist, I should stop the olive oil and warm water for a few years and see if I can get the wax problem to recur. But I don't want to sacrifice my comfort and hearing so I will just continue my current ear hygiene regimen.