I notice them mostly around the edging and sidewalks.
The wife get grossed out by them and when I sprinkle them w/salt they turn into a puddle of slim that doesn't wash off easily. If I sprinkle them while in the lawn, the salt kills the grass.
I do have some liquid insect killer that you have to mix w/water and apply w/a garden hose but, it doesn't indicate that it will work for slugs. It does indicate that it works for grubs but, I found that it doesn't.