Edward Scissorhands

In the 1990 film of the same name, Johnny Depp's title character is able to deftly use both hands to accomplish tasks with efficiency.

A pair of brushes atop the hitching post.

In working cattle, a critical-but-routine task is to brush the animals at the hitching post.  The animals are calmed by the act of brushing, they appreciate the routine, and they are much easier to catch and halter when they know the hitching post will have a pleasant activity to start.

Side note:  Animals that run off due to fear often run to the hitching post.  In the classical conditioning language of psychologists, the neutral stimulus of a hitching post has come to be associated with the pleasant unconditioned stimulus of brushing.  When animals are trailered to a location and yoked at the trailer, it takes on that same "magical" quality for the animals as a safe haven.

Anyway, to speed up the brushing, I often use a pair of brushes, one in each hand.  That way, I can cover twice as much coat at once.  With a full-grown ox, they seem to have about an acre of coat that needs brushing.  The animals like the extra attention and it speeds us along.