The SediMeter™ SM3B has a built-in cleaner. In many cases the cleaner is not necessary, but in certain cases it definitely helps out in long-time data collection.
The shuttle is hanging in a thin line from a reel on the top of the instrument. At a user-defined interval it is slowly lowered to slightly above the bottom, and pulled up again. A rubber wiper does an effective job at wiping off any incipient biofouling.