Blessed salt?  yes, that makes perfect sense.  Salt, like water, is something necessary for human life.  Salt also is great for preserving and purifying.  Salt was used to cure meat and fish, thus "preserve" it.  Salt can also be used to help purify by pulling out toxins.  Isn't this why salt baths are so popular, and so many like to bathe in the Dead Sea?  My wife loves to take a bath in bathing salt because she says she feels like toxins have been pulled out of her.  I have used salt to "purify" and old smoking pipe by filling it with salt and some alcohol.  In a few days the salt has "pulled" the old tobacco and impurities from the pipe bowl and "sweetens" the pipe (now I wonder, would blessed salt make my pipe blessed if used it to sweeten it? ;0)).  Salt is even used in holy water as a preservative.  I believe salt also represents one of the four elements (earth, water, fire and air) each of which has a blessed representation in our faith:  blessed salt (earth), holy water (water), burning candles (fire) and Frankincense (air).  Mark Kurlansky wrote a book called, oddly enough "Salt" which talks about salts history and how it was so valuable throughout history and in society.  An excellent read even though the subject sounds rather bland.  Anyway, I can see how blessed salt would be used in exorcism, because if salt removes toxins and purifies, then blessed salt would remove and draw out demons, which are are the most extreme forms of impurity.  Salt is taken for granted today due to such plentiful availability but this was not always the case.  Boiling sea water to get the the salt is very labor intensive and uses tremendous amounts of fuel for a very small yield. Salt is valuable on many levels, and deserves its place as a blessing from our Lord.  Peace, and a very Happy and Blessed New year.