My DD2 got a bottle a day from about a week old. She was a twin, and I was seriously ill that whole first year, so I used the bottle as a way of coping with the overwhelming demands I had on me. She had no problem going back and forth from breast to bottle, never had any problems with nursing. She was my easiest kid to feed, all round.
I tried introducing bottles to her twin, my DS, at that same age, and it was a disaster. He ended up with massive nipple confusion, after only two days. He started passionately refusing the breast, got himself terribly dehydrated and lost a half a pound, and we wound up paying out a pile of money for a lactation consultant to spend a few evenings at the house with me, getting it all sorted out. But once we got him back on the breast, which was a mighty struggle, he took up refusing the bottle, and refused it outright until he was a toddler.
My DD1 was also a nipple-confusion baby...
I think these things are more about temperament, than about anything you do or don't do as a parent. Some kids have no trouble, and others DO, and it's hard to predict ahead of time who's who. My point of view would be to try it-- try once daily, just a small amount-- maybe two ounces-- and see how it turns out. Be prepared to abandon it, if baby turns out to be one who's subject to nipple confusion-- you don't want to walk that road. On the other hand, if baby takes to it easily, and goes back and forth without trouble, I would guess three times a week should be enough to keep up the habit of how to use a bottle. (I am just guessing on that, though.)
