I would not advise using 'satisfying' in that context. That word can have sexual connotations. Did you mean 'greeting'? For polite, and formal, 'Hello how are you?' would be best. 'Hi' is much less formal than 'Hello'.

I think you should always use "hello" or "hi" before how are you if it's a stranger as this is the actual greeting part. Hello is more formal, but in many English speaking countries like the U.K or America "hi" is fine to use.