Their own private place gives them a sense of security. Confinement is NOT cruel unless abused. Do this by constructing or obtaining a box which will have a door or lid on it with adequate ventilation holes. The box should be big enough for the puppy to turn about in and even lie at full length, but no longer. The lid, or door, is required to keep the puppy from climbing out.
Airline crates work well.
Now, he might get caught the first night, but he won't the second. However, if the box is so large that he can relieve himself in one end and sleep in the other, he will do so. Bedding can be plain newspaper laid out. Remember that on the very first day it is important to start giving the puppy all his naps in the box. When the puppy awakens from his nap, you immediately lift him from his box and carry him outside to a spot which you previously selected.