Yes, it is possible and very similar to FSBO real estate. You'll want an experienced title company or attorney to handle the transaction. The problem becomes, where can you find FSBO listings for DVC? I've seen some on eBay, and there's a listing aggregator site that shows one or two.
The difference, however, is that, with normal real estate, there's a benefit to both the buyer and seller because of the reduced transaction costs. But with DVC and Disney's ROFR, there is really no benefit to the buyer. You can't really make a reduced offer, because, whether the broker is getting a commission or not, the total price paid is what Disney considers when they decide to take a contract.