We did this with our boys. The oldest picked up a sign we weren't even trying to teach: whenever I changed his poopy diaper I'd say "phoo phoo phoo!" jokingly a

We did this with our boys. The oldest picked up a sign we weren't even trying to teach: whenever I changed his poopy diaper I'd say "phoo phoo phoo!" jokingly and fan my noise. One day he was playing on the other side of the room and fanned his nose. He'd pooped and was telling us. Super cool.