Here I am back, even though I said I was going .....
I would very very rarely push a person. Why would I need to? - the person can talk, I can reason with them.
I can't reason with a dog. A dog doesn't know the personal history that makes my whole family (including extended family) really really nervous around dogs. So I have to use "language" a dog understands.
So I would use a stern voice first - go away. or leave, or no!, or something like that.
If a dog continued to be in contact with my family, I would then gently push them away with my foot (cos it seems at less risk then my hand). If this didn't work, as well as yelling for help and trying to locate the owner, I would kick out.
This is simple self- or child-defence.
If any dog owner has better advice about how to deal with it - which does NOT include letting the dog lick us, jump at us, try to snuggle in to us, or any any way be in close contact with us, then I would be delighted to hear it. But I doubt that there is a better way.