Well, let's see...
- You're describing a common scenario: someone is asking a question you don't want to answer.
- You've searched the 'Net and found a number of general-purpose responses to such questions... That haven't worked.
So what should you learn from this? Perhaps this: people aren't simple machines whose behavior can be readily controlled with a small set of standard inputs.
For decades now, cartoonist Al Jaffee has written a series of Snappy Answers to Stupid Questions. They're entertaining because they capture the sort of responses we often wish we could give people... ...but unless you're willing to be known as the smart-mouth jackass who never gives a straight answer, they're not a template for effective (much less polite!) communication.
Which means... You're gonna actually have to tailor your response to the specific person asking and question being asked. As past examples here on IPS have illustrated, the appropriate response to nosy questions depends a LOT on why they're being asked; a "witty" response might diffuse the situation, break a sacred social convention, or even put your life in danger...
If you want help doing that, you're gonna have to give us a bit of context: locale, setting, cultural background, etc. Questions here are expected to be based on actual problems that you face - so sketch out that problem as context for your question.