Cleaning block paving

[Wannabie]

Have red brick block paving on driveway. I’ve cleaned moss / weeds out but it looks drab and needs cleaning. I have a power washer. Only problem is there are no drains to push the water into at the front, and the one on the street is several houses uphill so I’m reluctant to clean using lots of water.

Any (pet friendly) suggestions?

Where does the rainwater flow?

A power washer should use less water to clean a drive than will fall on it during an average rainy day, so I wouldn't be too worried.