What is an 'o.h.'? What is an 's.o.'?

It's a reflex and I don't think you have control over it. Therefore, there is no right or wrong way about it, it's just how your body reacts and it just happens. That's part of the undeserved shame abuse survivors suffer if their bodies reacted, which was something they couldn't control (just like the abuse was something they couldn't control).