Muktiball training has many ways to execute, but often, coach has a bucket of balls on table or an elevated cart with a bucket of balls, stands near net or behind endline and machine gun fires balls away volley style to simulate opponent hits, they can also drop it on table and soft impact it right away to simulate a short push. Many ways to use this. it is called Multi-Ball Training. It is used by just about every coach where they can have a way to keep the balls in the training area.
Korean clubs are elaborate and have a netted off area for each training table, special ball pick-up tools that work real efficient, and a special extra large net on wheels they place behind table to keep the hit balls inside the net on wheels, they collect the balls in the bottom and funnel them down to a hole where they have a bucket to collect the balls. Every amature club in Korea has such a setup and many places in the world have similar special equipment to make multiball more efficient.