There's no canon that dates to anywhere near the 1st edition—WotC developed D&D in a very different way after the buyout, so I tend to make a division between TSR canon and WotC canon, because of the different design ethos.
My suggestion (and my conception of the "1e way") is to make something up the first time your players encounter trogs. The next time, use that again—and if they're smart, they'll know exactly what it means.
The advantage to this way of doing things is that your game will develop its own mythology and detail. You won't have to memorise it—it'll be part of your shared experience, and much more easily recalled than something you looked up in an article. The collection of facts about the world that "trog smell" will be a part of also gives your players a sense of a little bit of ownership and mastery over the world—they can be proud of their experience and knowledge in a way that they don't quite get if they're just reciting memorised canon.
This is actually one of the things that keeps bringing me back to 1e and 2e. The game is detailed, but there are enough holes for the DM and players to fill in, that the world slowly takes on colour and depth that's all yours. That's unlike other editions (or most other games) that hand you truths in the sourcebooks, to be contradicted at your peril. Of course, that's just me—that's not going to turn everyone's crank.
For what it's worth, I always imagined it like garter snakes or those black beetles, which stank when you caught them. (Of course I write in the past tense, because it's been a long time since I've been a kid down in the grass trying to pick up stinky animals.)