I agree with trying sugar soap appropriately diluted and a test patch. If you’re really worried then perhaps you could even tell the owners, with photo and ask what they would like done. If you make it clear you are being responsible and don’t want to cause them more problems they may be very happy indeed, rather than upset that you’re a ‘bad tenant’ if that is your worry

Definitely don’t use a blue chux my mistake and i have marks forever now

Always test an inconspicuous spot first with any cleaning. I wash my walls and ceiling with a diluted mix of bleach in warm water. That takes care of most spots

If it’s on the roof it might be a bit hard and dangerous to get to. I’d recommend a flat mop with a movable head and some hot soapy water, I’ve attached a photo of what I’m referring to. They have similar ones at Target for $6.

A Vinegar/Water mix on a soft cloth works well or, believe it or not Windex!

The safest thing to use is the magic sponge by Chux from any Coles store it works perfectly and doesn’t damage its very easy to use

Whenever I want to clean walls or remove stains I use sugar soap (diluted) and some warm water (keep well away from children). I find on my walls it is gentle and effective. Whatever is used it is always recommended to try on a small bit of wall and then see how it looks and if it is effective. Might also be a good idea to do some google searches on this issue. Home maintenance and cleaning sites might be useful? Good Luck!