They could be pissed and using it as a scare tactic.

Honestly, I think this is a b.s. tactic where they are trying to engage me into a bidding war (without for sure knowing if there is even "another buyer"(?)").

Do you many who find this tactic working?

there billing tactics are other than honorable and thats not the worse of it!

Not a good tactic to use on me. 

@Scott Weaner, depending on the company doing the imaging, it could range from wanting to replace the pipe at a cost of $3500-$5000 to just a cleaning to root removal which will be a few hundred $$.There was one company in our neck of with woods which has bright trucks (PM me for name if you want), who tried to replace the pipe and use strong sales tactics.

Hi Nathan,Out of area investing is a completely different tactic than house hacking as you know.

This is thinking as an investor and not trying to make a specific real estate tactic, "house hacking", work in a market it's not meant for.  

This might also be a good tactic if you are at the Fannie limit of 4 mortgages.Thanks!

Personal opinion only, but open houses are a sales tactic left over from long ago when the internet didn't exist as it does today.Today, it's simply a way to increase contacts and find more buyers; which I'm totally not against but doesn't do a thing to sell the home.