Do not put salt on slugs, as adding salt to the soil makes it unsuitable for gardening. Not the least toxic, but the easiest and most reliable method of slug control is placing poison slug bait around the garden, said DeAngelis. Metaldehyde is the most common active ingredient. Metaldehyde causes slugs to slime heavily, revealing their presence. Cereal-based metaldehyde baits tend to be more attractive to slugs.
Baits containing metaldehyde and carbaryl are considerably more effective, but are less common.
Follow label directions carefully when applying baits, he warned. Keep pets away. If pets have access to baits, substitute flaked baits or liquid for larger cereal chunk baits. Or apply bait on warm evenings after heavy watering. Late summer and early fall is a good time to bait because many slugs are about to begin egg laying.