Rubbing salt to wound!

It was funny.  The baby at home had a minor problem in her belly button, with a small portion of raw flesh jutting out and a moist layer forming on it every day and wearing out by next morning. Surfing the net landed on the problem as umbilical granuloma and several solutions discussed three ways of attacking the problem - mostly by applying silver nitrate, less so by copper sulphate and one by advising soidum chloride (for one week)!  So, there is some truth in the saying rubbing salt to wound - it may irritate, but it also cures!