This is exactly how i practice, except a few changes.
5 putters, from 5 different "tee" positions. After you throw the 5 upshots, throw all five putts from the furthest away lie. If you don't make all five, give yourself a point. throw from the other tees, same thing. Afterward, arrange some sort of negative consequence for each point... I used to do pushups, chin ups, 1 point = 2 miles treadmill etc. You can also arrange to get points for a successful round of 25 upshots, and count those towards dollars used for new DG gear. Whatever it takes to place pressure on those upshots and putts.