I use a conservatory ladder system made by Ultraframe
Ultraframe are the largest conservatory roof manufacturer in the UK. I bought mine last year and it cost me £600 but worth every penny as I soon got it back with the extra work I can now do.I charge around £80 to clean a 4Mtr by 4Mtr Edwardian which takes around 2 to 3 hours, this includes washing and polishing the whole structure including the cresting and finial ( the pointy bits on top) cleaning out the gutters and of course the windows. I don't recommend using bits of wood and rag as you will slip off trying to reach the cresting. I also charge a hefty premium for the window above the conservatory because without the proper gear my customers will never get it cleaned