Interesting. Some time ago we had to regularly clear a directory with many files in an ext2 file system. We ended up mounting a separate small volume at the point in the VFS. When we needed to clear it, we would just make a new file system on the volume.
Yes, that's for sure the smartest way to deal with it, if you have such a specific requirement. New filesystems (zfs, btrfs) with their sub-volumes also make that much easier, because they can dispose of subvolumes, and recreate them very fast.
