I've been sewing masks (just for the family, not to sell or anything), with a pipe cleaner in a channel in the top, as we all wear glasses. But in actually using the masks, we're hitting two problems. No matter how tightly the pipe cleaner is sewn in, it migrates to one side, and/or the pipe cleaner edges of the pipe cleaner pierce through the fabric. Anyone else have these problems or know how to solve?