From what I've read, a Roar Aggron is nice to have. Roar makes your opponent switch out which can trip up the baton pass team. Give it Focus Punch to take down Smeargle and Substitute to block Spore and Ingrain. It can also learn Thunder which is good against Baton Pass teams.
I've also read Perish Song is a good move to use too. It either forces the opponent to switch out or let their Pokemon faint. It gets passed on with Baton Pass which is awesome too. Just watch out for Ingrain though or your Pokemon will faint in the process too.
Those are the two best strategies I've read about. Baton Pass teams are really tricky and even these strategies don't guarantee a win. Good luck!
Aggron sucks because its awful (its also slower than Smeargle so gets Spored) and no Baton Pass team goes without Magic Bounce, Soundproof, Taunt or a combo of all of those but P-Song is fine.
Mold Breaker Roar/Whirlwind bypasses Magic Bounce/Soundproof.
Ghost type curse is cool too. Strips 25% of their health off per turn, it also bypasses sub.
Also i fail to see why Haze Quagsire didnt work lol.