I had real issues with chain suck on my hustler. There wasn't much space between the granny and the chainstay so it was really easy to stick in there and cause damage. It happened with dirty drivetrain as soon as it was even slightly worn. Tried everything as a protector but the chain just cut through it. That was zipties, reinforced tyres etc etc. Here's what I've done and it's totally eliminated it:
1. Dropped to a 2 ring set up (22, 34 at the moment but will change to 22, 36 when that wears out).
2. Took care to ensure that my chain was at just the right length.
3. Bought a E13 DRS, you know the dual ring one with the wee guide wheel and bash gaurd.
Like I say, totally gone. Did all three things at once so can't isolate the cause I'm afraid but it seems the only thing you haven't tried is the DRS. A bit costly so weight up any other suggestions before you splash the cash.