Cleaning sandstone, presoak recommendations, before pressure washing

G'day all

I need recommendation/s for solutions to soak mould etc on sandstone, prior to pressure washing.

This client has the dirtiest pavers I have seen around a pool/garden area, and I don't want to spend to much time and effort with a water pressure machine hacking at the surface. Sandstone can be soft.

I haven't had prior need for pre-wash solutions, so I need recommendations.

There are a myriad of products on the market. I just don't know which ones to trust.

Any ideas?

Thanks.
G

I have some stuff called Oxy Klenza given to me by a mate who's a stonemason, works well. I use it for removing mould off brickwork, but it's safe for use on sandstone.

Thanks richmond68
I did the job yesterday , using a liquid chlorine solution.
I'll keep your product in mind for next time [emoji1303]