7 bowls? I would not let any of my pipes go for more than 2. I prefer to run my pipecleaners through them while still hot (you do need to be careful removing the stem, but when cleaning hot you can remove more filthy moisture with a dry pipe cleaner before it dries to form gunk). I always remove the stems for cleaning, so that the pipecleaner can travel in one direction only, and then I can turn it around and clean the shank with the clean end. If you do this while pipe is hot, do not leave the stem out for longer than it takes to do your business with the pipecleaner, and then replace it (with care) immediately. Because I have smoked through and cleaned transparent acrylic stems, I have had the experience of pushing the pipecleaner one way, then back out, only to see how much black gunk gets returned to button-level that way - it has even caused the airway to be blocked! This was some time ago, and it may have been before I started cleaning while pipe is hot (I don't seem to have that problem now when I need to go in and back out through a stem to remove hot, gurgling moisture, mid-bowl). Now I suppose that if you get into bristle brushes and alcohol treatments, then perhaps you can get away with going all week between cleanings, but to keep spirits in the house and not drink them can be tough for some people.