That could definitely help too! I'm sure if he smells another dogs urine that could also help him to identify the potty area.
Another thing that might be backtracking a little bit; but what I usually recommend when STARTING to potty train a puppy that eventually will be an outside-only-pottier; is bringing the outside INSIDE. Like, have a shallow tray or bin and either cut out a chunk of your own yard; or actually grow grass in the tray with some dirt. It sounds really tacky but it definitely helps the dog get accustomed to the texture of the outdoors... It's basically taking the Grass Potty Patch idea except you use ACTUAL sod/grass. Eventually you just remove the inside one once the dog is used to going outside.