To complicate the situation further, there is no cell service in Afghanistan, shocker!

My Cell: 810.588.8154

For example, your cell phone.

Are there any devices that I can control from a few hundred miles away from my rentals?

I wouldn't expense a cell phone, internet or similar business expenses because there is no business justification to support it.

I have used closed cell foam on one of them, back when I started. 

As long as you don't eat the paint chips or try to sand down the sheetrock through multiple layers of paint without a ventilation device, it's not a big deal.

Get a loan (with a lender with more than 2 brain cells) when you buy again like the rest of the country and leave this one alone.

Feel free to reach out here, via DM or my cell is also in my signature.Cheers,   

Hi Ting,Maybe try going outside and coming backwards at it through the outside clean out.Be aware that some apartments have a device in the sewer line that prevents backflow into the other apartment--be careful to not destroy this.Some of them (not all) look like this.Good Luck!