Homemade monster spray is easy enough to make and can put a quick end to bedtime monster concerns. This strategy's effectiveness is dependent on the child (you know your child's personality best) and your powers of persuasion. There are two main types of homemade monster spray.
One is using a scented spray such as room air freshner or body spray. Print off a quick label on your computer clearly marking it as monster spray and then introduce to your child. Some parents prefer scented because children can feel better protected when they smell that it's "working." Simply spray in corners of the room, under the bed & in closets. Do not give to children to spray.
The other common monster spray recipe is adding a small amount of food coloring to bottled water. Be careful not to add too much as food coloring can stain--you can add a small amount of washable children's paint to color the water as well. Again, clearly mark the bottle with a picture of a monster crossed out or the words monster spray. Parents often give this spray to their children as a weapon of sorts. If they see any monsters, the child can spray them and the monster will disappear. Give the bottle to your child and let the hunting begin!