The zeolite in it will make that bedding last a long time, especially with only 3 hens. I use shavings and scoop out bits of poop w a pooper scoop, so I rarely change bedding.
I've used Flock Fresh the few times TSC carried it around here, as it is cheaper than Koop Clean which is the same type of product without the alfalfa. I changed completely to this stuff 3 years ago & it keeps my winter coop much drier than pine chips & is easier to clean out in the spring. It is expensive, but I like it. Koop clean at my feed store is $18.99 a bag & the Flock Fresh at TSC was $13.99, but they don't have it anymore.