I know that the OP post was "washing and cleaning" but I'll add what I did as an aside/addition. This was my first time so don't take this as a recommendation, just an example/experience.
My roof was in pretty good nick but for a rather noticable area that was either bird droppings or someone polishing had left some polish on the roof, anyhow I decided to do a repaint, like the OP mine is navy blue.
I got the Renovo 3 bottles (there is a kit but it wasn't available so I got individually from amazon): -
Disclaimer: The below assumes you also read and follow the manfacturers instructions.
1) Fabric soft top cleaner
2) Dark blue soft top reviver ( colour / paint )
3) Ultra proofer ( protection )
Was all easy to do, took me about 6 hours but mainly that was because of drying time, the process was: -
1) If you are doing this uncovered ensure to do on a day that is overcast and VERY unlikely to rain.
2) Jet wash the roof
3) Apply cleaner and scrub in with a medium brush (not too soft but not hard enough to damage), I actually used a nail brush. Making sure to get it into those areas where it gets mouldy like stitching and joins , leave on for a few minutes and go over any really mouldy or dirty areas again if they are still giving up muck.
4) Jet wash / rinse thoroughly, will take a number of washes tio get rid of it ( white foam washing across the top ) especially in joins where it has soaked in.
5) When totally dry mask off. I masked of all windows and to mask off the black plastic trims I opened the roof 3 cm or so at which point the trims come away and are easy to mask.
6) Start painting the roof with a decent 2 inch paint brush. Important tips below:
a) Don't do this in direct sunlight or it will dry too fast.
b) When you get drips or runs on your windows (and you will) ensure to wipe them off before they dry, the instructions say it is water based and can be removed easily which is basically true but it is still a pain once dried, especially on a plastic rear window.
c) Do this in small panels with two sides e.g. the middle of the roof down to an edge perhaps 10 or 12 cm wide, the reason I say small panels is that each panel will have 2 wet sides, DO NOT let one of these sides dry or you will get a line (and I did, right down the middle [
] ).
6) After it is totally dry (about 3 hours, read the instructions) apply the Ultra proofer in the same "panel" manner as above.
The results were excellent ( excepting my line down the middle but you really have to look to see it) it really looks like a new roof so thought I'd mention my experience. I can't comment on the longevity of the proofer but the brand is well known so I'll assume it is reasonably good.
Hope this helps someone