The ineligibles that I recruit in DII almost always show up, if I spend enough recruiting money on them. I always add several more home visits than I need to up his interest in the school. Of course, spending more money on them has become a lot harder in 3.0 because we don't have as much money.
The other thing you can do is promise them 30 minutes + start. You don't have to keep the promises the following season, but it does pose the risk that they will pass their SATs at the last second and then you are stuck with the promises. But that's rare, and the promises do seem to help significantly in getting them to show up.