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.
Caring for the donated cadavers used by a biology department for their pre-med anatomy classes. These were people once, almost always of a John/Jane Doe situation. Very gross and off-putting job, even if you could manage to not wonder about the lives of these former people.
I was very grateful that none of the cadavers we had at my medical school were John/Jane Does, and that we have a memorial service for the cadavers every year and invite the families to express gratitude.