to make a bad thing worse
To make an injury or insult worse, like how salt hurts open wounds. Have you ever cut your anything and walked into the ocean?
If by salt rinse you mean saline solution, then yes. You can use saline solution on any open wound to clean it.
People did that because it helped stop the wound rotting. Now people talk about it because it stings mightily.
The phrase "adding insult to injury " (making a bad situation worse) can be intentional or coincidental. However, the idiom "rubbing salt in the wound" usually means deliberately making something painful even more painful (as salt would be to broken skin).
Salt the Wound was created in 2001.
Salt the Wound ended in 2010.
The duration of Salt in the Wound is 1.63 hours.
The term "Pouring salt in an open wound", means that you are causing hurt to something that already hurts. If your ex has hurt you and they keep hurting you and you want them to stop, then yes by all means tell them.
it means to make something more painfull
Salt in the Wound was created on 1969-08-10.
To take something that someone says with a grain of salt means that you should not necessarily believe everything he/she tells you.
If someone is in a bad situation, "rubbing salt into the wound" means to aggravate that situation: make it worse. This is an idiomatic extension of the actual physical pain one experiences if an open wound is exposed to salt.