In a squirt bottle, pour the distilled white vinegar and the lukewarm water.
Next, pour the salt into the same squirt bottle.
Put the nozzle lid on the squirt bottle, and screw it in place firmly.
Shake the squirt bottle for 30 to 60 seconds vigorously.
Remove the nozzle lid again.
Drop in any essential oils being used - if any.
Replace the squirt bottle nozzle once again and shake vigorously.