In answer to the question posed by oakydoke, I'm using Peco code 100, ballasted by the usual method (but with N gauge ballast) and weathering with rust coloured paint applied with a small brush.
Not accurate to scale I know, but gives a good overall impression for my scenic layout. I will change one day, when someone points out an easier, more realistic and cheaper (in that order) system.
Until then, I'm enjoying myself anyway, so who gives a damn?