We have acquired hoarder homes with dead animals, infested properties, etc.

You simply find a closet that’s large enough and slap a dead bolt on it.  

Is it worth it to follow up with type of lead or should I consider this a DEAD lead and move on?

Mail them every month and keep it constant so they realize you are dead serious about your offer to purchase their portfolio. 

ROI diminishes with time.If you value cash you would never allow it to sit as dead equity.

High tides raise all ships"  - this is why you're seeing traditionally dead markets growing.Never a better time to be a flipper.

From what I heard, the people behind the home warranty fix issues within the property very poorly and when it comes time to replace an appliance, they give you the dead end of the stick and say “it isn’t covered”.

I graduated with an architecture degree two years ago and thought that all I needed to do to become financially free was to get the best job possible that payed me well... dead wrong.

As it turned out, the house had numerous defects and I told them we would have to renegotiate or the deal would be dead.

@Peter M. nailed his response dead on if you dont have drainage issues.