This recommendation applies to the Foam–Silicone Tips only. Over time, memory foam loses its shape, especially with nightly use. That means less comfort and reduced noise-blocking. To keep your Dream plugs performing at their best, clean both the ear tips and earplug body before every use, make sure the ear tip is firmly attached before inserting, and replace the Foam–Silicone Tips after 100 uses. The Double Tips, made entirely of silicone, last longer and don't need replacing as often, but the same cleaning and fit-check rules apply