This thread reminds me of a conversation one of my drop ins, who just happens to be quite a precocious and religious 4 year old.
DCB: Miss ****, Did you know that we are not allowed to say Oh my (whispers) *God*?
Me: Why yes I did!
DCB: But Miss ****, did you also know that we are not allowed to say Oh my (whispers) *Goodness*?
Me: Oh, I didn't know that! Well, what can we say then?
DCB: *Big dramatic pause* Oh my. That's it. Oh my.

So that's my guideline. LOL.