

Yeah, and also the Oxford comma is in my mind much clearer. I think if you are understood you are using the language correctly. If you are not understood at first but become understood after a bit of back and forth then you are using the language and also pushing the limits a little, making changes along the way. It is an evolutionary process, not design, so it is messy.
Consider doing a small test section in one corner before trying anything. Also take a clear photo in full daylight before you start and make comparisons with full daylight pictures later. It is very easy to have the lighting and perspective completely change how something looks, so make the comparison as apples to apples as possible.
Also, using plain water for a simple rinse can be very effective at removing dirt just by rinsing and repeating, no soap. This is lower risk than many other approaches but requires you fully dry before checking the result. Definitely research other options, but it may be good to try cleaning with plain water.