I am not going to claim that the idea of a chain for your mask isn't, at first pass, a bit weird. But at second pass it seems to be rather sensible. Besides, let's face it, the whole mask-related kerfuffle was weird until very recently. Yet, only this week, going in and out of assorted shops over the course of a day, I kept forgetting to take mine off.
Anyway, the canny specialist brand Sunny Cords has clocked that its pretty sunglasses chains can work just as well on your mask. (You put each elastic strap on your mask into the rubber loop at either end of the chain, and then tighten the loop. It's straightforward, but there's an instruction video on the website just in case.)
I like the Bead It style, which comes with a silver-plated chain, and beige, light or dark blue beads, and the McTassel, which has a cord and tassel of cotton plus gold-plated heart and beads, and is available in a range of neutrals and brights (both £29. sunny-cords.com). At another level are the semi-precious iterations, such as the lapis lazuli or rainbow tourmaline takes £92.
All of the above can, of course - as per their original conception - be worn with your sunglasses too. Perhaps, here's hoping, by a pool.