Wet method, here. I fill an empty 1 lb. powder bottle 2/3rds full with bullets, cover with water and then some (maybe 3/4ths full), add 1/2 teaspoon of moly powder, seal it tight and give it a ride in my rotary tumbler for an hour or so. I use foam padding to brace the bottle in the tumbler. After an hour or so, I drain the liquid into another empty 1 lb. powder bottle for reuse. Obviously, larger containers allow for more bullets. The coated bullets are poured out onto an old towel, wrapped up and rocked back and forth a few times to dry and remove any excess. Final drying is done in my brass dryer. They come out looking like black chrome and not nearly as messy as dry coating.
Do wash your bullets first, or the coating will not come out even. I use hot water and Dawn for washing, followed by a rinse with cold water.