Stir, agitate, swirl, etc until salt is dissolved.
Put in spray bottle & mist away!
Note: Don't mist it if you don't want it dead. Weeds shrivel & brown in 2-3 days. I've also used ice cream type salt with no noticeable change in effectiveness.
Easily increased using 1 part salt/2 parts water.
As always, keep away from small children who may be young enough to ingest it. (Eww!).