To answer this, I would refer you to a message thread over at the men's tennis forums site where somebody did the research on these kinds of scorelines since 1980. See here.
On the women's side of tennis, I'm sure this has happened many times where the winner won 6-0, 6-0. You tend to see those kinds of scorelines once or twice for each grand slam tournament where a player like Serena or Sharapova beats a low-ranked opponent 6-0, 6-0. I don't think I've ever heard of a match where the loser recorded a 6-0 set against the winner though (where the winner won their two sets by a score of 6-0 also) - that would be very rare. I will research it though and post an edit in here if I can find a record of it ever happening.
Here is another good read about the types of scorelines you're asking about - which mentions that it's a more common score in the women's game.
EDIT: Ok - I found only two matches so far that fit your criteria (both on the womens side). If you look at the match results for this player (Ka-Po Tong) from 2000 - scroll down to the Shenzhen tournament and the SemiFinal match. She lost the match 6-0 0-6 6-0. Then in Fed Cup Qualifying rounds in 2003 - Maria Fernanda Alvarez (BOL) d.Zara Desilva (BER) 0-6 6-0 6-0 . You can find that result here.