There is another fake frumkeit concept about not using the young lady's first name until the third or fourth date. The explanation that I got was that this too is too personal. And God forbid you should get slightly personal with someone you are contemplating marrying! Granted that this is more of an extreme frumkeit thing but some take this seriously - as long as the 'frum' moniker is attached.
I feel that most of the time, the best way of dealing with things is in a straight forward manner. So instead of trying to rework sentences so as not to use a person’s first name at all, the couple could use agreed upon pseudo-names. How about he be called 'Ploni' and she be called 'Plonis'. Just like in the Talmud. So the conversation would go something like:
Him: "Hi Plonis, how are you?"
Her: "Good evening Ploni. I'm doing well".
Or they could have the entire conversion in 3rd person:
Him: "Hello, how is Plonis today?"
Her: "Plonis is doing well. How is Ploni?"
Much better! It is all out in the open that he doesn't want to get to know her personally. And visa-versa.
I am not quite sure if the rule carries over into 3rd party discussions. Can you use the first names while talking to your shadchan? I think that should be acceptable but you never know. Maybe this could be the start of an even stronger 'chumrah'. The girls should always use the term 'bochur' and the the boys should use the term 'maidel'. So when talking to the shadchan, the boy would say "Yes, I agree to out with Maidel Moskowitz". Likewise, the girl would say "I agree to go out with Bochur Blum". You know, this might catch on!
Or, you could go the mentschlech route and have a normal conversation.