Rent or buy a power washer - plain water that sprays out under pressure.

Get a surface cleaner attachment to your power washer.

"Last summer I started to make an attempt with my power washer and maybe dish soap and stiff brush if I'm recalling correctly, but it barely made a difference."

Barely made a dent. Hence my request for a product.

I have good luck with Wet and Forget and I've also used a solution of Oxyclean and water. If it's a cement product, white vinegar and baking soda is supposed to work well, too.

Power washer has always worked for me. No soaps, etc. just plain water.

@graywings123 are you talking about those round things where the jet spins? Got one and that was less effective than going square inch by square inch.

Granted I've just got a light duty homeowner PW, 1400 PSI, but given how ineffective it was I'm not too confident that more power is all that's needed.

Oly, I'll look into the W&F.

Foas, I've not used it on pavers, but on Trex, on bluestone and wood fences, as well as real stone in my rockery, so assume it would work on pavers. Takes a while to work, but then it does!

30 Second Outdoor Cleaner30 Second

On this link that has reviews of "best deck cleaners", this is listed as best for concrete cleaning https://simplegreen.com/products/oxy-solve-total-outdoor-cleaner/

Sounded good to me. I have no concrete, so I can't vouch for any.

I keep getting ads for Wet and Forget (but I'm looking to clean pvc and mesh patio chairs, along with a stained wood deck). It does get mostly rave reviews.

We use a bucket of water mixed with pool chlorine. And a heavy duty scrub brush on a pole. The brush is mostly for spreading the chlorine mixture, there’s not a lot of scrubbing necessary.

Our 2000 psi washer worked well on Flagstone.

If your power washer didn't make much of a difference I suspect it's not dirt making the color darker on the exposed pavers. I'd try bleaching with a diluted mix on a few stones and see how that works.

Wow! Power washing can be very satisfying. When it works for you. Unfortunately it hasn't for me in this particular case, hence my request for cleaners.

I recently saw a thread about leaf stains on stone patio and they used a paste of Oxyclean and water to remove them.

Funny, I was just looking at a slideshow of before and after power washing photos earlier, which looked amazing. I too would be concerned about chemicals that can kill nearby plants. I wonder if a machine like the ones used for stripping wax off floors would work? Something with rotating brushes?

Sand blasting? (kidding, not kidding)

Aren't there products made specifically for cleaning concrete like that?

Sounds like your power washer isn't strong enough. You should be able to clean concrete with just water if you have enough power.

I, too, am thinking that your power washer isn’t powerful enough. Really, it can make a huge difference. According to my NextDoor app, powerwashing is a sidejob offered by landscapers, etc. Shouldn’t be too costly to hire someone. Have them come out to ”prove” to you that the results will be what you want before you hire them.

I'll start by trying a more powerful PW. Thank you.

I have to clean my brick paver patio, and find that liquid dishwasher detergent is pretty effective.