The means are limitless I agree. However if they are derived of consent and outside of control, the plan of eugenics is doomed to failure without coercion of some kind to assist it along the way. Perhaps the incentive model could work, although I doubt it. For the main reason that most men want to raise their own children, women too. Biological rejection is a real phenomenon which few can fully overcome. Unless you completely overhaul what people think of as a family and can rewire the instincts of people and offspring successfully, you have a mountain to tackle.
Is it possible? Sure, but I only see it being viable under force where violation is punished in some way or another. The other problem is that people are emotional creatures. The heart wants what the heart wants. Even if X has a terrible genetic profile, he makes breakfast just the way you like it, is good with kids, has goals and dreams and blah blah blah...
People make emotional decisions all the time, marriage and children being one of them. Other factors being the promiscuity of the current society makes it difficult. Odds are accidental pregnancies from one night stands aren't the run of the mill olympian or particle physicist. But rather the dregs of society. From real world experience, I have only noticed that morons typically reproduce more often that our brighter minds. These are the same people that smoke, drink, and do drugs of their own free will(
not brilliant life decisions, so why would they be more wise with their reproduction?). I highly doubt they will go away regardless of any incentive to control their numbers short of a rifle butt to the base of the skull. Low caliber life forms seem to be inevitably more numerous that higher caliber life forms.