:)hello, a local landscape gardener gave me a load of shrub and conifer clippings, they like scratching around in that keeps them occupied, and its easy to clear out once a week, put in composter or green wheelie bin and then u can clean the paving easily before replacing, the gardener has to pay to take the stuff to the tip so was happy to give to me, maybe there is one in your area who can help you out. just check nothing that could be poisonous or knotweed etc
hope this help
claire