Gave the bike a very thorough wash and scrub, polished the paintwork and went to get some Scottoil FS365. They didn't have any in my local place, but for the first time ever, I found ACF-50 on the shelf so thought I'd give it a spin (very expensive stuff - £15.99 for a can, is that a lot more than others have been paying?). Disappointed in that the spray doesn't atomise very well from the can, but used a cloth soaked in the stuff, so shouldn't work out too dear that way. So she's all clean and protected for now, but as I like to wash off road dirt before too much accumulates, I guess it won't be long before she needs doing again
Although having said that, I usually only use clean, cold water from the garden hose to wash her down, warm water with a rag to finish, and then polish on the paint. So maybe the coating will last a while.