Very grass roots, personalized marketing, and got a few responses.

If you close on the property and then discover the roof is leaking, the main sewer line is nothing but tree roots, really any major expense, that can easily put a borrower in a position where they do not have enough actual cash to solve the problem, so the property loses value due to deferred maintenance, or the borrower digs themselves into more debt, making it even harder to get another loan to cash me out of the equation at that upper 20% of equity.

Over time the waist lines (used to all be cast iron, will need to be trenched and replaced with PVC out to the street connection, as the cast iron breaks down over time, allowing tree roots to enter and clog / block the exiting waist water.You best best is to call a local plumbing company, ( plumbing 911, mr plumber, rotor rooter) and have them come out and give a quote on repairing all the items the inspection found.The plumbing issues on a duplex may be more manageable then say a 100 plex with a broken waste line or main water in line, but size and scope is everything.

Has anyone found a particularly effective yet still easy solution for dealing with tree roots in sewers?

I suggest asking yourself "why" 5 times to get to the root of the desire to invest.

Clogged toilet, appliance repair, tree roots in sewer.

Before the backhoe business (which is going to be expensive) consider running a camera down the line starting from the clean out to determine any issues with tree roots. 

I will be following and rooting you on friend.

If you are trying invest out of state close to your roots here in central Illinois I can definitely help you develop a solid plan going forward.

This let's me know which ones I can root out from the start.