While away at work,I have seven or eight pipes with me to carry the load for the 4 to 7 months I'm gone.Each pipe gets smoked once or twice per day.They're all pretty well hammered by the time I get home again,even with a monthly cleaning. When at home,I don't follow any rotation,as I own well over seven pipes in total.I just allow those 7 or eight working pipes to rest unmolested. ?