Have you tried this? It takes forever to clean out a bucket. At the scale we're talking about, doing this on a single thread from the CLI tool means you could go home and come back the next day and cancel it then, and you still wouldn't have made a particularly big dent in the bucket. It's really a pain in the neck to delete a whole bucket full of data when you actually want to. It's "easy" to start off a recursive delete, sure, but I think you're overestimating the "kaboom" factor.