Well, I went out and bought the Workz model battery powered washer and as far as I know this is the first time it has been used for cleaning stal. For a start it i simpressively light and compact fitting in a medium sized pelibox (apart from the hose and optional head extender). We fed it from a 5 gallon can hauled up a steep slope to the entrance and manhandled through an awkward crawl and a steep slope to the site of action.This was a lovely stal boss covered in mud in an area where the tapes have been ignored. No problem with battery as I used the smaller one and still had plenty of power after the water had all gone. The jet width can be varied and the washer comes with a soft brush. I just used the jet on the second to narrowest settin gand it worked a treat virtually restoring most of the stal boss to its original state. Obviously a convenient nearby source of water would be useful or the siting of several buckets under drips prior to the trip. No doubt if the Old Ruminator sees this post he will be able to post some before and after photos.