The Why stage has begun...

I was just warning Russ about using Why questions with Aylen. I told Russ that Why questions should be avoided because a lot of time you don't know why, and when asked why you are immediately put into defense mode. Counselor 101 stuff. And I added plus we don't want to encourage why questions in fear of starting that fun, charming, long lasting why phase. And whatdoyaknow. It started.
AJ: help please. ( pointing to the comb he threw over from his bath)
Momma: ok. (I put it into bath)
AJ: help please (again, throws comb over)
Momma: nope. I told you I'd only pick up toys once.
AJ: why.
Momma: because I said.
AJ: why. Why. Why. Why. Why.
Momma: (thoughts- I need to google. What do I say? Omg here we go. But seriously what is the best answer?)

Oh dear. Any advice welcome.
Love,
Momma