Ok I think I have this down, with an on disc song and solo. I have checked it 4 times and I got it easily each time. I will describe exactly what I did.
Requires 2 mics
Song: The Look
Difficulty Setting: Medium
Section : Start of the 2nd verse "Fire in her eyes......"
This section has a two part harmony where they sing the same thing and has a 3rd part that is a talkie at the end of the phrase over lapping the other 2.
Method : I was using a Rock Band mic and a lips mic, I held the the RB mic close to my lips and the other one an inch lower around my chin and out away from me ever so slightly. SO when I sang the fire in her eyes part I nailed the 2 part one, and the talkie bit gets tagged on for the triple at the end of the phrase.
If you have trouble with the end bit just shout it, you should have the other 2 full before it comes.
Mic volume was set right down on both mic's
Note: this may be just a total fluke with my setup just thought I'd post it in case it helps someone else.
Edit: I did this on medium, but I can't see why you can't try it on easy too