buy your milk in Canada - or anywhere else in the western world - where rBGH has been determined to be too dangerous to add to milk
rBGH isn't added to milk; it's injected into cows. The misconception that the milk itself necessarily contains rBGH is precisely the justification that Monsanto claims for restraining "rBGH free" labels. I don't think that's an adequate justification, though, and I agree with the thrust of your point.