Glad to see I'm not the only one who was shocked to see #onlyconnect putting its weight behind this rubbish. I know the question was about things people do for luck and they do actually do this. Trouble is it damages the statue, blocks the pavement and isn't even a long-standing tradition.
#onlyconnect perpetuating the myth that locals rub Greyfriars Bobby's nose for luck. Tut tut. Tour guide nonsense.