Use cuttlebones for all flock members here, the whole thing or half per flight/cage/etc. … Never in 20+ yrs. have I ever had any kind of problem with using them and I have a huge flock of many species of parrots and birds. Sure, there could be a rare accident, anything is possible but the benefits far out weight any remote possible risks IMO.
I recommend our members keep one in every cage. If you are still worried about sharp edges or whatever, I suggest you break off the hard shell part and serve the rest, either in chunks or in powder like was previously mentioned. Like was also previously mentioned, some birds take a real long time to start nibbling or chewing on them but IME, eventually they all do. Just leave one in the cage and sooner or later the birds will realize what it is and the benefits to them to eat it.