I think most adults would find this method condesending. I can't quite picture the reaction if I praised my spouse for getting up on time in the morning and going to work. Or cooked his favorite meal because he didn't get loaded and steal grandmas jewelry over the weekend. Adults don't need to be praised or rewarded for just doing the right or responsible thing.
However, if someone knows that you deem them as being "lesser than" or if you want to keep them dependent on you, or looking to you for validation...then give it a try. Sort of like "look at you, you made potty in the toilet, such a big boy!" Or "give me your paw, good girl, you get a treat now".