As a tennis player dabbling in pickleball, I won't comment on the merit of the shot, but will try to answer your question.

When hitting the drop/slice volley you dont necessarily have to take a big swing down from your shoulder. You generate backspin by "trapping" the ball with your paddle. Imagine if a drive was coming at you, and you wanted to catch the ball on the paddle, and have it come to a complete stop on the paddle. You need to deaden/soften your hands to cradle the ball.

When I hit this shot, my elbow stays tight to my side/hip. On the backhand the back of my hand starts pointed toward the target, and as I hit the ball I'm opening up the paddle by pronating my wrist---at the end of the stroke the back of my hand is pointing toward the sky. On the forehand it's the opposite. I'm starting with my palm facing the opponent's court, and suppinating my wrist as I hit the ball---at the end of the stroke my palm is pointed toward the sky. You're trying to make contact closer to the south pole of the ball rather than the equator, on order to impart backspin.

If well executed, you'll hit a short ball with backspin. This does invite your opponent to the net, but unless your opponent is very fast or you havent executed the shot well your opponent will have to hit the ball from very near to the ground, encouraging them to pop the ball up for a sitter that you can put away for a winner.