I started having snail problems in my back yard last year and tried sluggo to get rid of them. It reduced the number of snails, but it did not kill the eggs. Hence, many more snails this year. I read that they use ammonia sulfate in England to kill snails and it dissolves snails just like salt. Ammonia Sulfate is used as a fertilizer, 21% nitrogen. I have used it in the past to quick green my lawn. I spread it all over my back yard, lawn and flower beds. Snails are gone! It dissolves them quickly and completely. Only the shells are left. I let it sit on top of the soil in the flower beds (mostly roses), for a couple of days before watering well. It will burn plants if too much is applied, but it does not need to be applied heavily.
I have two cats that spend time outside. I kept them in for a couple of days just as I would if I applied any other chemical fertilizer. The ammonia sulfate dissolves when water is applied. So there is nothing left on the ground for animals to eat. Ammonia sulfate is cheap. About $6.00 for 20 lbs. My lawn and plants are green and the snails are gone. Problem solved.