As an alternative and in addition to the wee-wee pads, which some of the pups started using at a week and a half old, we set up a boot tray a week or so later filled with natural hardwood pellets. I chose a boot tray since it has a low profile and easier for young pups to get in and out of. I decided to try the wood pellets after speaking to a breeder who has been using this method for years and recommends it.
What I like about the pellets is that they have no chemicals. Yeah for chem-free! Pups like to romp and take naps in them. What I am not sure that I like is if the pups are ingesting them while I am not there and when they urinate on them the pellets do get crumbly. When this happens, the powder gets all over them.
This is a safe and natural pee-spot for pups, with the added benefit of a new sensory experience beneath their paws. It’s important for pups to feel different kinds of surfaces, and this is a way to do that while giving them a place to go when nature calls.

UPDATE:
After using the boot tray we used under-the-bed boxes, kitty litter boxes, then we moved onto a 30″ x 36″ tray that is used in the bottom of metal rabbit cages from Tractor Supply. It’s called the DuMOR Rabbit Tray.