The minister for Kenmore in the late 19th C , the Rev. Mckenzie not only recorded a lot of rock art but described the use of marked rocks in and around homes of his parishioners as effectively charms .When you start to add reuse in forts/duns ,brochs , homesteads,churches , townships ,hut circles , enclosures etc to the souterrain record we get past the 140 mark and counting ,and that excludes possible reuse in monuments like stone circles , chambered cairns , cists etc. Pretty powerful and long lasting ju ju .