Dead Rat Odor Removal?

We just had to clean an apartment where the tenant had cats that used the entire place as a litter box. I ripped up the carpet and the old linoleum tile underneath. Mopped the floor many times with soap/water, vinegar/water, ordorbane ( commercial stuff) and a few other things. I still could not get the smell out. I rented an ozone generator and ran it for four days. The smell is gone. I found a janitorial supply place than rented the machines for a small fraction of the price that general rental places got or restoration places got. Search around.