That really suits my taste, very well done and then even done yourself. Great. Please leave out the pressure washer, it washes out the surface and more green algae accumulates. Natural stones should of course stay, that's my opinion. If you want to do something, then scrub with Lithofin green deposit remover in spring so you don't slip on wet slime. If that wouldn't be a problem for you and is interesting: at cemeteries there are often border slabs made of gneiss, which is a black-white-gray mottled stone. The municipalities are happy not to pay disposal costs. Likewise, garden landscapers on construction sites who process natural stone. Collect leftovers and then gradually dispose of them. We bought all our material cheaply from exhibitors after a garden fair and also processed it ourselves. Since the fair has not taken place for the second time, one could go to building material dealers and ask for material from the exhibition. If you're lucky, you might still get a laying plan with it. The companies that participated should be listed on the organizer's website. They might still have palletized goods, also with laying plans and pictures.