I hope people see this, I tend to come to munsnet as a 23 year old for product reviews and mumsy help and advice on various things.
Not sure if I can add photos, but when the rubbery texture gets wet it has started to split and can fully come off of the head. I think it must be water related because the one I keep for cleaning my coffee grinder is fine.
One of them has fully split and broken off, I have checked and they are still selling them but their lines closed at 5pm.
It's especially dangerous as they are designed for 2-6 year olds using on their own.