I whipped up a batch for the 03/04 season and used it last year 04/05 and it worked just like it did the first year so I would say yes, IT CAN BE USED FOR CONSECUTIVE YEARS, as long as you kept it well sealed in the off time.... as for its effectiveness... AWESOME... had deer all around my stand on my trails and never even flinch.... "Ghost Juice" tm ...Don't leave your truck without it!!