Here are a few polymer clay beads that I made especially for creating hemp chokers. The opening is fairly large (3mm) so the beads can also work for small to medium size leather cords.
These are three that I will send you, as pictured. Please check the photos carefully for imperfections and irregularities - these are not perfectly round.
I am not sure how long this type of bead will ultimately last. I usually make sure to keep them out of the extremes of heat and cold and avoid water. These were produced in 2002 or so. I've had my own in-use beads of this type last about 20 years with a fair amount of wear. These have been in storage since made.