I just turned an old chapstick tube into an earplug container. I pried the bottom adjuster wheel thingy off, pulled the screw stick thingy out, and cleaned it up real good. I shoved two of the tan HEAROS plugs in there, and it was a perfect fit. I could not get them out at first, but when you remove the bottom part, it leaves a small hole in the bottom, and to remove them, I just blow into the bottom on the tube, and they just shoot out.
So if anyone needs something to keep a pair of earplugs in, and they have an old chapstick container laying around, its worth a try to see if they fit.