Many Thanks for the reply.
In short "No I hadn’t" that’s because I didn’t know what was possible with a WFP system and thinking about it, this would have been a much better question to have asked in the first place
I thinks its because I have heard of so many problems with "first cleans" plus the fact that these are minging made me think it wasn’t possible.
So it leads me on to ask "How good is a wfp system in this situation" could it cope with jet fuel residue covered with cobwebs (no doubt caused by dust from the building site over the road)?
We are still looking for a WC contact in this area as we are primarily office cleaners, is there anyone that would be interested in these works? (although still subject to tender at this time).