The affectionately named Chain Pig makes cleaning your chain that bit easier thanks to a hook that slips over the lower jockey wheel on your bike's rear derailleur, removing the need to physically hold the cleaner while you cycle the cranks.
While the hook won't fit inside a short cage downhill mech, it can be slipped over the lower guide wheel of some chain guides (with the bike upside down). The Chain Pig is solidly constructed and its array of brushes means you only need to use a small amount of degreaser to deliver a shiny chain ready for some fresh lube.