Smell in bathroom- cannot get rid

[Mak K.]

I am working on a remodel project for a property which turn out to be a nasty house with poop infested. The people for some reason had water turned off and were doing the deed every where. In fact the toilet was stuff with baby diapers and poop never flushed.

anyways we got the house cleaned up and disinfected. The only place we are having issues is one of the bathrooms where we are not able to get rid of the smell. During cleanup the crew did spill over gray water but did cleaned it up and bleached it. The toilets are all removed and discarded. The smell is not for the pipe. 

This is second story and has tiles. We are not sure if water seeped in the tiles which does not look it would. 

Anybody with similar experience on how to get rid of the smell? It’s nasty but it is what it is…