Oh yeah, one issue with this though is your source. See when I did it as a DJ, I had the instrumental and acapella on a 12" so they were both the right BPM.
But for example, if you download the full song or instrumental from YouTube then download the acapella from some other YouTube video, there's a good chance the BPMs are different.
So I recommend getting the full song, line that up with your drums, then line up the acapella over all of that. You might hear the acapella slightly out of sync with that of the full song. So just tweak the pitch to get it right.