You need to post a couple of pics or be specific. Yet all these people throwing out ideas and no one has a clue what you’re cleaning. Is it residential sidewalk in a neighborhood or city sidewalk with restaurants, heavy traffic, etc.
Plus you’re saying you’ll use too much chemical downstreaming but then you’re talking about going stronger. Which is it. Questions w/o pics are just for conversation because everyone guessing. How wide is the sidewalk? How’s it drain, never mind, just post pics or give a lot more details
Lol I mixed oxyclean and bleach together in a back pack sprayer like 10 years ago…it completely blew the top off of it…luckily it wasn’t on my back!!!..lessons learned the hard way🤪
