It works well, but it might be cheaper to use a dehumidifier. I use calcium chloride to dry out what I'm about to smoke in the next week. I fill an aerosol bottle cap with calcium chloride, and rubber band a coffee filter on top, and put that in the jar I'm currently smoking. (it will make it bone dry)
Low humidity in flowering will mean quicker transpiration and less surface area required to transpire. Less chances of mold, etc.
Good ventilation is usually adequate in keeping humidity levels low, however.
