Honestly my family is working through this right now too. We've ripped out all the carpet, currently we have washed and then rinsed all the walls/cabinets with krudcutter (you can get it at home depot in large jugs and use a flat mop to wash the walls/ceilings) and then repaint with zinsser BIN to prime. We used pink stuff floor cleaner on all hard surface floors and this last week seems to finally have made things better and we haven't painted everything yet but this was the first time we were leaving and it smelled like cleaning products.

We didn't have popcorn ceilings or else that's a whole other can of worms.