Well I thought it was a good idea to combat the rising sea levels

Actually, thinking about it, the rising sea levels are not really anything to do with global warming.
Put a load of ice into a glass then fill to the brim with water.
As the ice melts the water doesn't flow over the sides of the glass - so melting ice caps shouldn't cause rising sea levels.
However.
Look at all the carp we shove into the sea.
Millions of tonnes of scrap metal on the sea bed from all the numerous sea and air battles, all the car ferries etc, the many thousands of supertankers filled with oil and the many more filled with thousands of huge metal containers - not tomention the many thousands of subs, carriers, destroyers etc belonging to all the countries of the world.
I wonder if anyone has ever stopped to calculate the total displacement of all this stuff
Going back to spraying brine, I wonder, if winters are getting harsher, we'll see a spraying system being added as an aftermarket thing for cars etc?