Really hoping the answer is no
If you need to use a lot of water and live with balconies or windows below, make sure you warm your neighbours or be cheeky and do it when it is raining.
Bear in mind that if you can't get to the outside surface to clean them, they'll not be able to inspect them anyway - unless they are really dirty and the dirt can be seen from ground level.
Our new place has the other sort where each slate is attached to the next with cord. You can flip these.
The mounted hinged gate type: you can unhook them, they are not very heavy but better to use your strongest friend, and take them to the spray power hose type of car wash. This is very quick and effective. Stand them up to dry and hook them back on 2 hours later.
For the roller style,
I use a steam cleaner starting at the top. As Tom says, if you can't see the dirt, neither can the inspectors.
See if Spiderman is available?
Check the "Merkblatt" (information sheet) you received from the property manager regarding the handover. Sometimes there are exclusions. If not, then they must be done properly. The professional cleaning firms have the expertise and tools needed for this. If your building has a professional firm looking after cleaning and maintenance of the general areas, try contacting them about the shutters.
And no flat above us sadly, even if I was willing to hang out of a window We will do everything we can, and as there are no exclusions on the checklist, we will simply have to hope they don't bring a really long ladder to reach up to our level! At least the ones we can get to on the balcony will be spotless so hopefully that is all they look at...if not, then I guess we will end up paying for a company to come do it anyway and likely they will try to do the entire building and charge us...!