If it's precured, it probably won't cause a full blown cycle like uncured rock, but since it's being shipped there will be some dieoff, so you should expect at least a mini-cycle.
If you are wanting to add it to an established tank, my suggestion would be to treat it like uncured rock. Put it in a big rubbermaid tub with some water, a heater and a powerhead and cycle it like you would a new tank, testing the ammonia/nitrite/nitrate levels daily and doing water changes as necessary. I woudn't think it would take more than a week or two to cycle it (since it's precured). JMO