you can make a garlic solution at home, that's what people used to do in Russia. "Soak 3 crushed garlic cloves in 1 tablespoon (15 mL) of vegetable oil overnight. Then, strain the liquid into 1 litre (4.2 c) of water. Pour the mixture into a spray bottle. Add 1 teaspoon (4.9 mL) of liquid soap to the solution, then shake the bottle before using." you can spray it directly on snail/slugs, soil, plants, etc.