Little League - Senior Level Softball

[cmmguy]

I have a question about substitution in Little League - Senior Softball.
I know you guys have a little disdain for Little League but around here we get treated pretty good. Many of our girls play varsity HS ball and travel Ball, but fit little league in because it truly still is girls from the neighborhood and not recruits...and they have a lot of fun.

On to my question: Tournament Substitution Rules(3.03)

Player A is a starter. She plays two innings.
Third inning(which inning is not really important), we substitute Player S in for Player A when we go to defense. An inning passes and player S comes up in the batting order and we want to bat player A, so we substitute Player A in for Player S, she bats, inning ends. As we go back on defense, we sub Player S back in for Player A. We continue to do this. Using Substitution effectively as a pinch hitter.

Is this legal?

Notes:
No minimum play requirements at Senior Level and I can find no rule prohibiting back and forth substitution.

Thanks for your input and consideration.