bubbaking, one thing I've actually realized is that if you stand grab or pivot grab, if you time the pummels well (You can't buffer them), you can force a ground release. If you dash grab though, you can force air releases on Mario, Luigi, Pikachu, Kirby, G&W, Yoshi, Popo, Olimar, Jigglypuff, Lucas, Ness, Squirtle, and Wario. Although, you can't force a ground release if you dash grab. Dedede imo has an above average grab release game (Pretty good, but nothing extreme like Bowser, DK, Marth, and Charizard have). He mostly has grab release stuff on pretty poor ground and air release characters.
Here's all of the followups he has:
1. Ground release infinite on Ness where you dash dance into a pivot grab. It's kind of cool, although the only problem is that you can have a somewhat good chance of tripping and for only dishing out 3%'s on early percentages. I would say the best thing to do it shield chaingrab him to the edge and at like mid to high percents do the infinite for like extra damage or even enough to kill him with a throw.
2. Dashing air release chaingrab on Squirtle, which is good for positioning him off of the stage and his crappy recovery. You can even do walk offs on Squirtle like every mid and heavyweight except for Luigi.
3. All of D3's air attacks, f tilt, dash grab, up tilt, and up smash on Wario. Most ppl prefer up smash or up tilt for kills and fair or bair for damage racking (I would bair for early percents and fair for mid percents).
For the Lucario matchup, I guess you can just fly in the air and catch Lucario since he's not that fast and his projectiles aren't really fast. Send him off of the stage a lot because bair is good on Lucario and his recovery is pretty crap. Also, don't rely on d throw to up smash all of the time or kills and probably just stick to up tilt for the most part because d throw to up smash is pretty hard to perform (It's frame perfect) and it can't be done when d throw is stale. Plus, Lucario would like to fair you a lot so you're better off going with an up tilt than a grab.
I think that d tilt could be good as a grab release mindgame. It's pretty fast, disjointed ranged, and kind of strong for a tilt.