It's a bit of a dark saying, as it references the historical practice of using salts as a laxative, and the implied urgency of a widow to relieve herself.
Here's why the saying works:
* Salts as a laxative: Salts were historically used as a powerful laxative, causing rapid bowel movements.
* Widow's urgency: The saying implies a widow's need to be discreet and quick in her personal needs, perhaps due to societal pressures or fear of judgment.
The saying is meant to be humorous, but it's important to note that it relies on outdated and potentially offensive stereotypes.
Instead of using this idiom, you could choose a more neutral alternative like:
* Faster than a speeding bullet
* In the blink of an eye
* Like a shot
Remember, language evolves, and it's always good to be mindful of the potential impact of the language we use.