Very clever, and the straws made them pretty colors that will show up on a variety of fabrics. I have been using ear plugs similar to these:
https://smile.amazon.com/Macks-Ear-C...able+ear+plugs , and they almost never fall off for me, but this could be a worthwhile way of making some in colors that would contrast with fabrics that are too similar to the ear plugs.
Anyone who hasn't tried this pinning method will be pleasantly surprised at how much of an improvement it is over using safety pins.