Can I reuse cotton covered wax earplugs?

So yeah, I am looking to buy earplugs and I remember from Grey’s Anatomy that one of the character uses wax ones because they are apparently effective. Previously I had used foam ones but they weren’t that great.

So all the wax earplugs on ebay are covered with cotton and I am wondering if I can reuse these safely? If so, how long of use would I get out of each pair?

Also any recommendations of other earplugs is, err, awesome.