(as an aside, sad to see posts by 'Bushy' still readable on this thread, passive aggressively winding up and mocking people who object to racist murder and corrupt white policemen. Can't a mod expunge them?).
We’d have to manually search for every post he’d made and delete it. Then delete the embedded content within any reply quoting his post.
Aside from rendering any reply absent of relevant context, it would take about 30 seconds to delete each post on average. If we guess that he made 2000 posts and each was quoted twice on average, that’s 50 hours work non-stop. I think you’ll be hard-pressed to find a mod willing to do it!
TL;DR? No.