Go to a hardware store and they make heavy duty pick tools for mechanics and such. I use the Craftsman brand pick set, they are about 6" long and have clear plastic handles. The whole set was like $10 at Sears Hardware and has 4 different style picks with handles on them similar to a screwdriver grip. One of the picks in particular has almost like a double bend to it, it is nearly perfect for a 1st gen iPhone disassembly, no bent aluminum housings or broken fastening tabs anymore!!
This type professional pick is WAY better than dental picks because they always seemed have to much flex in them to actually pry off a stubborn 2G back housing.