The danger is when people used untested chemicals for untested purposes. This can lead to injury and death, under certain circumstances. Obviously not soapy water, but there are countless examples. That's why these laws are written. Additionally, if you are producing a food product (honey) it behooves you to follow the law even if it seems stupid, to protect yourself and your customers.
For example, if you pour oxalic acid on your bees, are you sure somebody eating the honey won't get hurt from residual acid? Or crude thymol? That's why carbolic acid is no longer approved for taking honey off, too much would wind up in the honey. But I know lots of beekeeper who still use it. A lot of beekeepers are scofflaws. Too bad, because that can give honey in general a bad name.