My dad had some interesting-acid stories, when he was a young chemist. They both involve cleaning glassware. The era is around 1970. One was something he said

My dad had some interesting-acid stories, when he was a young chemist. They both involve cleaning glassware. The era is around 1970. One was something he said resembled a wok full of the usual suspects of strong acids. Overnight, the mixture was hygroscopic, so they'd start it heating up in the morning to dehydrate it and increase the concentration. To test if it was ready, they'd throw in a small piece of wood, about the size of a match. If it disintegrated on contact, it was ready. Then you could dip your glassware to clean it. But, in another lab, they would use a small bottle of hydrofluoric acid at the bench, taking a layer off the glass at the same time. While the dangers of large exposures were well known, he did mention the nerve damage and it being highly annoying and painful if trace amounts got under your fingernails, a somewhat common injury of the lab that everyone simply tolerated. He thought the latter was a more convenient arrangement.