When I made a location to word system I ended up having to spend a huge amount of time on the word list to try to remove words that tend to combine negatively. Partly because of that (but also because I went slightly more accurate than w3w and with a hierarchical encoding) I needed 4 words per location.

Still, I think it's a nearly impossible task.

Have you considered moving?

one of the features is that the spot a couple of metres away will have an entirely different set of words