I have used them and still do. Yes, I wash them and store them in a mason jar without the lid on it to make for easier access and as I add more I just press down and they crush. After the jar is full I empty it into a thick plastic bag and start over in the jar.

I believe they help with slugs to a degree then I use shallow pans of beer if I see a slug hole.

p.s. If they were not washed I think they would attract critters like raccoons and perhaps cats.

I used to use them around some hostas. I let the used shells air dry, then stored them in a large empty coffee can(s) - crushed them into sharper, smaller pieces by using the bottom of a smaller canning jar. No, I didn't bother to rinse them first. If they are thoroughly dry, there shouldn't be any smell. I have a good nose and that never presented a problem....no matter how long they were stored in that air-tight container.

I stopped that particular slug-control for two reasons:. 1. It wasn't effective enough and 2. I didn't like the messy look around my pretty hostas. I love the healthy looking dark soil to showcase my hostas.

I just thought of something, Beverly! I should start saving them again - to crush and mix into the garden soil as an amendment instead. :)

I am very pleased with the success I have had the last three years with slug pellets. The slug population in my garden has diminished considerably. I do find some holes in the thinner-leaved hostas but that doesn't appear until quite late in the season and by that time, my vigilance has already subsided since the dormant process is not far behind at that point.

My additional, regular ammonia spray/drench applications in early spring take care of any new or old slugs...then it's pellet time for rest of season.

I crush them and put them under the compost I'm putting on the beds. I also use coffee ground and coconut earth. I will also try a solution with essential oils which worked great on my roses with some of the hostas. Maybe the slug won't like the smell and taste of it. Just testing:-)

I inherited a healthy garden and decided to do my part making it better 10+ years ago. I researched organic methods of pest control and started crushing eggshells and sprinkling them around my "designer" hostas. Seems to have discouraged pests since I've not seen a slug in the years since.

I don't wash the eggshells; I simply toss them in a container inside my garage and let the weather/nature do the job. I did lay down corrugated cardboard and topped it with 6" of pine bark mulch so that may have been a factor in snail control over the years.

I use them all the time. I do not rely on them for slug proofing my hosta, but use them underneath the hostas that are being attacked most.
I simply rinse the eggshell under cold water and then store them in a large paper back beside the compost collector on the kitchen counter. Every so often, I crush the eggs in the bag for more space. They do not seem ever to attract mice or pests while being stored.
My first application will be in spring when the snow leaves.

Thank you for all of your responses. I don't have a big slug problem. However, I recently read that crushed eggshells also deterred Japanese Beetles. So I have a couple of spots in my garden where I have hosta below and climbing rose, a beetle attractor, above. So I thought this is where I would use them.

I used to use them. For the last few years, my garden has been terribly neglected, but I am retiring in June at the end of the school year, so I plan to get it back into shape. That means using egg shells again! They do seem to take care of the slugs-those sharp edges, don't ya know!