Seeking brilliant ideas for 100% washable distressing solution for aluminum walls

Hi Art Cube, Seeking brilliant ideas for 100% washable distressing solution for white aluminum walls. Quick scenic? that I hope someone might be able to help me with. Working on a gig in a huge warehouse that has white aluminum walls (pic attached) that we cannot paint but we need to somehow distress (dark) and the key is: must be washable (power wash?) when they wrap in a few weeks. Looking for ideas/ suggestions.. It's too much area to cover to do something like hairspray/ streak + tips, so looking for a low cost solution to basically distress/ dirty it up then be able to powerwash it clean in a few weeks which is key. Do you have any ideas what could be a good solution? Dirt? Charcoal? or perhaps some other brilliant solution that I'm not thinking of? All ideas welcome & appreciated. Thank you in advance.