how do you clean the windows on the outside?

[mousymouse]

we live in a flat on the third floor. windows are "cleaned" by the property management every 2 months but its pretty useless. they just hose the window down with a telescope brush thingy.
anyway we have some bird poo on the windows that just doesn go away and the windows are pretty grubby from the outside.
I*ve seen the window wizzard presentation on tv, but the reviews on the internet are not very good. of course windows open to the outside and there is no way to savely clean them from the inside...

I bought some magnetic window cleaners for this purpose from the Ideal Home Show a couple of years ago and as you clean the inside a string attached to the same cleaner works on the outside and is magnetised so it moves in tandem with the inside cleaner. Trouble is that the magnets are so strong they're dangerous and could cause some damage if you cuaght a finger in them so they're just sitting in the understairs cupboard now and I'm afraid of ever using them again. Sorry it's of little help but it is a warning to anyone thinking of buying them.