I treat all of my water by taking it to the pictures and then for dinner and a few jars in the "Reservoir Keeper and Laudry Maid Arms" It's usually Ok with that. Wot other people said - you're in much more danger of squitters by touching handles in railway carriages on your way to Scotland or sleeping with strangers in bunkhouses, bothies and hostels. Avoid rubbing itchy eyes and get paranoid with the alcohol gel and you'll still get the squitts! Enjoy the time in the loo/ peat hag/over the wall in the woods by yourself. Try not to make too much noise. Take a book. And remember that sphagnum moss is God's gift to those with a sore bum.

Thanks a lot to all of you for the answers and comments...
Now I'll try to sort it out !