I suppose it does make them use their muscles.
However, some snakes are such shy eaters, they will not strike nor eat while being watched. I rather leave a dead rodent in the enclosure to walk away and have them eat without constricting, then leave a live one and walk away.
The "drop" method usually still elicits a strike and constriction. The only time I've seen them eat without constricting were the instances of very shy Ball Pythons.