Honestly, all I did was dry my hands with the paper towels provided in the gents, giving them a good rub all over. Then I used a second towel to clear up residual damp patches, and realised how light and airy my left-hand ring finger felt.
I peered into the bin of crumpled up damp paper towels and something gleamed back at me, so it wasn't too hard to retrieve. Must be more careful in future.
I thought fingers got gnarled and knobbly with increasing age. Mine seem to be slimming down.