I hear that some people spray garlic water on their plants. Is this good? Will it prevent additional fruit from bearing from the already existing flowers?

Should I add anything else to the garlic water like dish soap? Any perticular color? How much is enough per gallon?

I almost forgot to ask......will garlic water prevent those hornhorms and other insects that might be eating holes in my still green tomatoes?

When is a good time to apply this garlic spray? In the morning or in the evening? Should I also water the tomatoe plants with this solution once or twice.