As a hammer and DS-man, should I farm Deviljho?

I know what missions he is capable of appearing in:

Bye-Bye Bloom (Six-star Village Crimson Qurupeco hunt in the Flooded Forest) and Hair of the Dog (Six-star Village quest to deliver Slagtoth oil); I believe the HR Qurupeco (and his Crimson brother) is the first monster capable of calling for Joe, and I am considering spending several quilliard (read your Hitchhiker's Guide) Bye-Bye Bloom and Hair of the Dog runs to attempt to learn (and maybe eliminate?) the Pickle from Heck.

Yes, I know he can appear in Siren's Song, but, that mission honestly costs too much.

Is this worth it? Or should I use a couple of moments during the above missions to simply learn Jho's tells?

I wouldn't farm him, as you can't make any of his weapons or his armor till you get to 8-9* Village quests. His armor pieces all require parts from monsters around that level, and so do his weapons.
If a jho happens to appear during a quest and drops a shiny, then go ahead and get that though. As you'll be able to get Talons that way which are the only things worth getting at this point in the game.

Oh.

I guess I have to wait until Joe's hunt quest comes up before turning him into hot dog condiments.

If you are not doing group content, the first time he appears on a quest on his own... is after you have finished the game. No joke.