Q.how to use coffee grounds for slug prevention
I am interested in learning more about organic methods to control or deter bugs for flowers and vegetables. Do coffee grounds work or because of their acidity can they cause more harm than good?

This article talks about a number of ways to control slugs organically: https://www.gardeningknowhow.com/plant-problems/pests/facts-about-slugs-and-how-to-kill-garden-slugs.htm
I've heard people mention coffee grounds, but the consensus of opinion seems to be that coffee grounds don't really work very well to repel slugs.