ORIGINAL: SeamusG
A spade bit with spurs was very effective when cutting thru a large number of ribs. I wouldn't mess with one unless it has sharp spurs. Also, use two pieces of sacrificial wood - one on each side - to eliminate splintering.
May have to check out those Forstner bits - love to have an excuse for more tools
Been using the Forstners for years and they are great. I have an inexpensive set from 1/4-1" and they all fit a 1/4" chuck.