I didn't have much success with the beer. Yeah, it drowns 'em. However, the scent of it also attracts more. (Hint ... place the bait at the perimeter of the garden to draw them out of it and to intercept tourists. Also, apply the DE as a perimeter barrier. Double whammy, apply the DE in a band several inches away from the beer saucers. Draw them through the DE.)
I have used raw coffee grounds with total success for two years now. Sluggo worked for me, too, but I was concerened about using it continuously and building up the phosphate levels in my soil. Diatomaceous earth is also 'organic' but loses effectiveness when wet.
I'm going to stick with the fresh coffee grounds until it stops working for me. I spend a few dollars for a 5 pound can of whatever brand is cheapest at the moment every other year ... it's cheaper than just about any other method. (Beer, diatomaceous earth and Sluggo aren't free, either. And even though salt might be a permitted product in the organic garden, I don't think it brings the side-benefits that coffee grounds do and I simply don't think it does the other soil life any more favors than it does the slugs. Sodium chloride is a poison at elevated ppm numbers and it is very easy to get to those numbers with the micro-biota of the soil.)
I haven't any way of checking, but I am convinced that the caffeine also leaches downward at a high enough concentration that slugs and eggs hidden in the mulch at the soil line are also affected. They just take forever to return. I have made three applications in two years and, in that time, have seen only two more slugs and no more damage.
I am also helped by having my garden in well-raised boxes. This makes for a longer journey for the tourist slugs and no cover for them in my paths made of bare soil.
Bill