I plan to leverage my Chemical Engineering income and real estate income to grow my multifamily real estate business significantly.

If the area is that harsh to where I need a drone like what the bombsquad uses just to check out a house - I'll pass. smh :-)Kudos,Mary

I know that sounds unduly harsh but for most agents that is true.Since most of my rental property has been purchased out of state I interview a lot of agents and those are my basic questions.  

And most buyers were VERY leery of rehabbers in general; mostly because it's so uncommon there;-  The weather is harsh and the market price differentials between summer and winter are extreme. 

Sorry I sound harsh, but if you want to make money in business, you have to sacrifice something in the present in order to get a big payout in the future.

A word of caution muratic acid is a dangerous chemical that one should know how to use before attempting. 

Are they usually so much a heat loss during harsh winters that owners block them up or what?

And landlords who own the fewest units are the most vulnerable to total destruction, especially in "tenant friendly" (let's not be too harsh and call them "anti-landlord") states.

I searched on the internet for drain flies and tried almost every chemical that claimed to kill them.

Listen to the advice that successful people are giving you and use it as a tool for learning something new instead of consistently replying with an excuse of why you don't have the time or why it won't work for you.Again, I am sorry to be so harsh but hopefully it's something you need to hear and will help you long term.