We tried a few weeks ago (Bath area), but no-one would take them. If they bothered to respond at all they just said no thanks, and if pushed I think one or two cited hygiene reasons for refusing them… They weren’t even particularly old or tired (we just had too many after pooling our resources) and we ended up redistributing them among family as spares, but that’s only putting off the inevitable disposal, I think.
Disaster charities prefer money to buy new in bulk, apparently. To be fair it would be a logistical nightmare trying to sort through random donations and ship them in.
We didn’t try animal shelters, so that might be your best bet.