I’m not asking about the worst job. I’m asking about the grimmest one. For me it was when in my teenage years I was making candles you would put on a grave. Most of the time is was just filling the form, burn the right shape and passing it forward. But sometimes I had to fill in for a person who was selling these things, and that is where it gets grim. It was decades ago but I still remember one lady who asked what would be the best candle to memorialize her late husband. And she gave me the whole life story of her and her husband. I shit you not, it was the most touching love story I have ever heard. I quit the next day.
In my industrial mechanic apprenticeship I had a stay in the maintenance department. In the time had to clean out a several hundred liter tank of spoiled cooling lubricant of a CNC machine. If not maintained properly it becomes a breeding ground for bacteria and fungi and it almost made me puke the first time I broke the surface of the waste at the bottom of the tank after pumping the fluids out. It didn’t get much better when I had to shovel out the rest of it.
I will never work in maintenance again.
(Edit because I tried something short because I wasn’t able to comment here last time I tried)