I have to agree with the force fetch. If done right it seems harsh and the first time I did it it almost broke my heart. I raised labs for 30 yrs and this is by far the best method for training a dog to hold a dummy/bird until told to release it.
I don't like the command "drop it". Especially if your dog brings back a live pheasant and you tell him to 'drop it'. Then you have another retrieve.
My commands were fetch (to hold) and give (to release).
A smart dog will learn in about a week of short lessons. And he will remember it the rest of his life.