In my area lots of contractors make a clamp on blade for landscaping that clamps onto the bucket.
I seem to notice that they generally make it about twice the bucket width or slightly wider.
I've seen a variety of attachment methods ranging from simple clamps to welded up sockets that fit the bucket teeth.
On the other hand I don't recall a factory type accessory being offered but could be wrong.
More experienced operators seem to master the swing from side to side technique probably because the don't want to lug around and install/un install another device.