i tried using just pure water before and it takes ages! you guys not found you have to scrub for ages??
i just got a 10 litre pump sprayer thingy me bob! it will shot to around 3 storeys in height, so for a 2 storey house would be fine.
i know you've got it in the morning neil but load yourself up with some tfr comes in mighty handy...looks like your just gonna be scrubbing like mad, although i wouldn't of thought it would come off but if these guys say they've got it off before then you may well.