That seems a bit much, you're liable to scare away good talent that way.
"Sorry about this but we've had some candidates passing others code as their own. So we've been asked to take all candidates through some code line by line. Such a pain but we have to do it unfortunately. Ill try and get through quickly. You dont mind do you?"
What would be disrespectful was if we ignored all your hard work and hired someone not half as good as you because they had more glowing reviews or more stars on their repos."
Obviously I'm no hiring manager, but often a bit of honesty goes a long way.
And it can lead to very interesting discussions, you learn a lot about a candidate that way.
People, in general, like to talk about themselves, and engineers like to talk about their own code. "See this if statement, well there's a funny story behind that...".
A few years ago I interviewed a candidate who mentioned Github on her CV but no actual URL. What's your username on there, I asked, let's look at some of your code. She refused and said she didn't want me to look at it. Then why did you mention it on your CV I asked? Because she was told she had to, she said. All in all a weird experience, probably for both of us.
Of course I've never coded in a professional capacity, so don't mind me if I said something stupid.