water and vacuuming works for some stuff but does not work for heavy or should I say dense things like metal shavings. I have had to lift the tiles to clean. I have a light epoxy under the tiles so dirt and spills show up. Also the little channels do drain water away but they also will fill up with debris like hair and grass clippings to say a few. Think of it like your floor is a sluice box the little channels will keep heavier debris from flowing.
I would also be mindful of larger debris being pushed through the openings that won't be vacuumed out.
I like the tile and its great for washing my dogs or car without sitting in puddles but they are not perfect and will need to lift them to clean under the tiles if you are a little OCD.