Hickory Dickory Dock (and other similar forms) was used as a children's counting-out rhyme in the North of England and Scotland. The suggestion that there is a basis in shepherds' telling-numbers (Hevera, Devera, Dick, for example, in Westmorland) seems perfectly reasonable, as these were still in common use when the rhyme began to be noticed (first publication seems to have been in Tom Thumb's Pretty Song Book, c.1744). See Opie, Oxford Dictionary of Nursery Rhymes, no. 217.

I think that we can safely leave those pesky druids out of it, though.