They do the job of trapping ear wax. Be nice if there was a trap adapter for a syringe to blow out the trap, with either air or a liquid, using the same black plastic pins the hold the trap replacements. It shouldn't sell for more than $5.
These hearing aid tips (wax traps) are an exact fit and are easy/intuitive to remove and replace. The pricing here supports changing them more often, which I have found to increase hearing aid effectiveness. Recommended.