I have tried some Facebook groups down there and they are ALL (so far) nothing but spam and scams, or people advertising to clean cars, etc. 

Make articles or targeted advertisements emphasizing your desire to buy houses to flip.Driving for Dollars: Search for foreclosed or distressed properties as you drive through areas.

Depends on where you are getting your prospects.If from Airbnb, VRBO, etc. then they won't be expecting either.If you are getting them from your own advertising, then put your requirements in your ads and definitely have on your website.

NAR is requiring us to use a buyers rep agreement which was always recommended but never enforced and buyers agent commission is no longer able to be "advertised" on MLS.

When I see houses in C areas in need of rehab being advertised as 150 a square foot by wholesalers as well as on the MLS, it makes me realize it will likely be slim pickings for a while.   

We advertised the open houses in the MLS listing (see #3).  2. 

Also, try to find the CPA's and attorneys that deal with them and do the same.2) see #13) Advertise where they go, so you're top of mind when they want to sell.

@Steven Wocknitz @Luc Boiron @Julie TohIn Ontario, and I imagine in the rest of Canada too, hard money lenders (called private lenders in Canada) are not allowed to advertise unless they are licensed mortgage agents.

How & where do they advertise?

The internet, gurus-advertising constantly in reels feeds, and TV shows has killed this industry.