What about Exeggutor w/ Confusion and Psychic now?

It depends on your local meta. If his cp is high enough, or can get high enough, to sit in gyms, you should certainly put him in there. IMO confusion is the key, whether it is on him or Slowbro, the thing hits like a truck. I have always preferred seed bomb because I find multi bar charge moves better on defense. That being said, psychic is tricky to dodge, so it can really put a dent in someone.

Confusion w/ anything hits really hard. I always train up the gym when I put my C/Physic or C/Solar Beam Exeggutor in the gym so they have to defeat it 2 times. I have a 2300ish C/Seed Bomb, but idk a Fire Type like Arcanine or Charizard can take a hit or two. Getting hit by a Physic or Solar Beam would be really painful. I think of him as a B/HP Poliwrath before the bubble nerf.