While I was out walking yesterday, up around Northumbria with my friend, Ian, I realised two things: first was that Ian and myself hadn’t been on a walk together since before I went to Edinburgh, more than fifteen years ago; second, that I didn’t know how to clean the pipe of a water skin. These things are great in general, but can be tricky to clean, and you have to remember to empty the water and dry them. Last time I walked, I left some water trapped in the pipe and it went green. How to clean it?

So, here is my solution: cut a piece of cotton thread about three times the length of the pipe; about half way down tie a small piece (about 2cm) of hemp string or something similar; feed the end of the thread into the pipe — getting a couple of cm’s is easy, more is hard; now, dribble water through the pipe. The point is that the flowing water removes the friction between the thread and the edge of the pipe, and slowly pulls the thread through; you just have to feed the slack. When it’s all the way through, you can pull the string into the pipe; again, keep the water flowing or at least full of water. You can use the string to scrub the insides.

Originally published on my old blog site.