Maybe they are not actually out to harm Obi Wan. They are the homeless droids of the galaxy, insisting on washing the ship for Obi Wan.

subtitles could get this across. Careful removing of actual damage could help sell it. The fog on the window could just be from some sort of cheap form of washing fluid.

It could be funny if Obi Wan had a line along the lines of "No, I just had it washed!"

then of course, one tries to go ask R2 if he'd like his dome wiped down, which he refuses intensely.