Not all the time, but for a major meltdown when nothing else works? I have done it a couple time with Ben when he just gets so hysterical he can barely catch his breath. I blow gently in his face and he just goes into reflex mode where he holds his breath for a second. It can be just enough to break him from the hysterics and back into the kind of cry or fuss I can calm him from.
The thing is... I feel bad for doing it! Should I? There is nothing really harmful from it, right? It is just triggering a natural reflex to help calm him back down. Reassure me on this!