Thanks for the response. My idea was to eq one of the tracks a little higher and add reverb to it. That way I could avoid reverb on the low end of the spectrum and one track would be dry so the lyric would come out a little more. However, you bring up some good reasons not to do it.
Thanks again.
It's not necessary to do what you're thinking about to achieve a clean, audible vocal track.
Doubling is a technique used to fatten a vocal track and make it thicker but even with a single vocal track you should easily be able to get a decent quality with reverb and the track still be crystal in regards to the vocals being heard clearly.
The song you mentioned is a single vocal track with verb on it and you can understand the words.