Since the cafes were opened, the amount of Sluggo I have used in each cafe has been reduced. Only about a half-dozen Sluggo pellets are used in each cafe. The reason for this is the chipmunks like to get into the cafes if very much Sluggo is used. I get rid of the chipmunks (relocated to a beautiful park) and place a rock on top of the cafes if they are broken into. The good thing is if a chipmunk or other critter breaks into a cafe, not very much Sluggo is lost.
The cafes are used to keep the Sluggo drier, longer. Haven't had to use much Sluggo each year and have kept the slugs under control using a minimum amount of Sluggo.
In 2009, I put baskets over the saucers to keep other critters out. The baskets are staked down with plant stakes. Since doing this, no critter has raided any slug cafe.
I have also used ammonia spray (10% ammonia/90% water) first thing in the morning to kill the slugs. I don't have to do this very often. In 2014, I got a headlight so I can hunt the slugs during the night. The ratio of ammonia/water has been increased to roughly a 50/50 mix with no adverse affects on the Hostas.
The combination of Cowboy slug cafes and the ammonia spray have kept the slug population down.