We fitted some of the class 158s with sand boxes, which was OK while we used ordinary sand except that it made the problem of the train vanishing off the signal box track circuits worse. (The leaf gunge was fairly good at doing that already!) So we added metal filings which were supposed to cut through the black Teflon like coating that crushed leaves become. That sort of worked, but it was still touch and go as to whether a train would stop or not when approaching a red signal, and whether the train was actually visible to the signalling system. It could be quite worrying when a passenger train played "Now you see me, Now you don't" as it approached a busy junction.
Sand in gel squirted on to the rail head? Why not give it an exciting name mmmmmm! let me think! AH ! SANDITE!?
Just over the road from where I live all the wagons with bright blue tank containers come in every January for an overhaul and cleaning. They arrive a dirty brown colour and go out again every September all bright and shiny.
