When doing a wash, i generally use windshield wiper fluid. I'm guessing you can find that across the pond. Its the blue stuff that comes in big jug. Over here its blue anyway, although I've heard that over there they also have green. Premis behind that, is that it dries much faster, and doesn't pool as much.
If you are going to order paints, i would try to get floquil or pollyscales rather than testors, but I dunno what the availablity for those is where you are???
Keep up the good work!!!!
D