Alas, the TA selected from those yellow pages has to be more than half-way familiar with OWE rules, or be willing to be trained by the passenger, a potentially time consuming and painful process.

The TA does all the dealings with the airline, and when the TA doesn't understand the rules and speaks with an airline agent who tells him, e.g. "your client can't begin a trip in Damascus because BA doesn't fly there" the fun begins. You have to convince your TA that you know what you're talking about, and the TA has to be willing to argue with the airline, and listen to the airline agent say "your stupid passenger is wrong." That's a pita even when the TA is in your time zone and has a good phone.

And the example wasn't made up: BA/Canada.

BTW, can anyone say anything about commissions to TA's in the countries of interest, from BA and the others? I understand AA and BA pay exactly zero in the United States, but since Emeco et al gladly sell tickets, that's not so everywhere.