Best way to clean balcony tiles in semi enclosed balcony that doesn't have drainage
Some porous stone can be damaged by harsh cleaning chemicals. I would probably start with a stiff scrub brush on a broomstick, with a bucket of warm water and a bit of TSP (trisodium phosphate). Just don't use so much that you create standing water.

Let that dry then rinse with a sponge mop and clean water.