Presently have six Greenwing Macaw (17 yo), Red Fronted Macaw (12 yo), Red Lored Amazon (17 y.o.), Lilac Crowned Amazon (about 43 y.o.) and a Congo African Grey (11 y.o.)
Panama Amazon (1 Y.O.)
Again, I could see doing it once precisely TOO scare the bird into NOT accidentally flying into the pool, AND for the purpose of showing them where the stairs are so that they can get out of the pool in the unlikely event that they did...
I can't see taking my bird in a swimming pool!
Unless it were something like a kiddie pool with untreated water. My big birds always liked playing in the kiddie pools...