Yes this does work, but you have to put a good amount of corn meal down and try to keep it dry. Corn meal will dissolve in your soil, if it gets moist or wet. Its said that slugs will eat up the corn meal, then swell up and die. But if it gets moist, more then likely your soil's bacteria and fungi will eat it, this will benefit your soils health.

 I use corn meal as a fungicide, either to prevent damping off or mixed with water for black spots on roses. Works great for lawn grass too!

Its best to use multiple methods when dealing with any pest. Try using coffee grounds mixed with crushed eggs shells too. Caffeine is a neuro-toxin to slugs/snails, plus coffee grounds are great for the soil as well. + worms love it!