Cone Filters can be reused over and over as long as they are properly cared for and they aren’t torn or otherwise damaged.
Rinse with hot water before and after each use. Do NOT use soap. Detergents can leave residue in the fibers which would cause off-flavors in your syrup.
Allow to air dry. Do NOT wring dry. It could weaken the fibers of the filters.
Store in a clean, dry, odorless location.