21 month old Suggestions

today is so hot that I decided our 21 month old son could go diaperless around the house. I brought his little toilet out (it's usually in the bathroom where he frequently sits on it and makes poop noises but has never actually gone poop or pee in it) he imediately went and sat on it and told me to sit in a nearby chair so I did. After about five minutes I started trying to entertain him so he'd stay sitting there and he finally ended up peeing. I gave him many applause and he ended up pooping and peeing in it several times over the next couple hours. He was very excited and proud. He's now napping (in a diaper) and

I'm a little surprised at how well it went and kind of shocked and unsure of how to proceed! Has anyone had luck with potty training NOT with the three day method? We probably won't be at the house all day everyday for the next few days but I'm wondering if he has a few hours a day diaperless if that would work. Any other suggestions or comments appreciated!!