In 1947 the first squeeze spray deodorant bottle was invented. In the 1960s spray bottles with trigger-style nozzles became popular. Modern spray bottles pump the liquid up through a tube with air pressure, so the liquid is forced out. According to the website HomeEverAfter, a test was conducted to find how much liquid is left in a bottle after it stops spraying. In a 946ml. bottle of cleaner, 147ml. were left after the spraying stopped.
Remove the nozzle.
Run warm water over the nozzle.
Wipe the nozzle with a tissue.
Scrape the nozzle with a toothpick to remove any debris.
Run warm water over the nozzle again.
Replace the nozzle.
If your nozzle still won't spray, remove it again and soak the entire nozzle head in rubbing alcohol for 10 minutes then repeat the previous steps.
If only a small amount of liquid is left in the bottle, add a few marbles, which will raise the water level.