Not sure about the wax ones, but I use 3M foam ones when I work with loud machinery. They are disposable, but I reuse them anyway. From a physical standpoint, eventually they flatten out too much and will not expand anymore. From a hygiene standpoint, I keep my ears pretty clean and have never had a problem….if I were going to use them every night I’d probably change them more frequently though and if they get dirty with grease or something I toss them.