Here's an article on the subject: https://www.washingtonpost.com/lifestyle/home/considering-having-your-air-ducts-cleaned-think-again/2019/01/28/cb5c14b4-1393-11e9-b6ad-9cfd62dbb0a8_story.htmlThe article is probably correct that dust trapped in ductwork is unlikely to become airborne.

that could be really be tough to do, the dust, the missing utilities etc.Net Net, I would pick a deal that at least shows a little bit of a return and analyze the flip separately and then any cost avoidance is a bonus.The deal doesn't need to be perfect as a flip only, it needs to do ok as a flip, and then the icing on the cake is you aren't paying rent.  

You may not be able to wholesale the house but you may be able to take it L/O or subject 2. its all about how many tools you have in our bag when it comes to cold calling.