I haven't used Facebook, but that sounds like a great method for finding buyers that I can implement. 

We're very interested in the BRRRR method, as entry is much lower, but we don't have the contractor experience or contacts for that kind of investment.

Newcomer here to real estate investing with an interest in long term SFRs and MFRs and short term rentals using the house hacking, BRRRR or traditional mortgage method.

However, I believe in the methods of many successful investors over the years and owe it to myself to give it a go.

Of course, the method of reaching them (direct mail post card vs letter) may make a big different in addition to the message. 

While out, I took notes down on vacant homes, taking pics, cross-reference tax records to see if a bank owns it, if not, send a yellow letter, or a different method that has been articled on here (take pic of house, print on letter and envelope).

I've always heard others say it the other way around, but your method does seem it would make them want to get the fees in to avoid being late on rent.

Is there another method (preferably free) to find out who owns a home?

When you start something new (a new rent collection software, new method for maintenance requests, etc.) how specifically do you go about getting your tenants up to speed?

The timing and method of disclosing is key.