After using my electric toothbrush I always rinse the whole detachable head, dry the bristles, remove the head and tap out any water. Yesterday when I tapped out the water (from the open end that sockets onto the handle) a tiny black speck appeared on the white porcelain of the basin. Hm, I thought.

I tapped it again, hard. And again. And with each tap, more and more black gunk came out. All in all it would have been about the same volume as four or five match-heads. Dead black, and when I cautiously sniffed it, it smelled like a very old and dirty blocked drain.

Argh! I’ve been putting this in my mouth!

I tapped it about a hundred times until no more gunk came out, rinsed it a few more times, then dropped the whole thing into a glass with Steradent (a solution used to clean dentures, retainers etc) for half an hour.

It smells clean now, but I think the message is to clean those electric toothbrush heads thoroughly each time, sterilise them occasionally, and replace them more often than some of us probably do…