Grip accessories and rowing machines serve very different roles. Grip accessories are small tools that change how the hand connects to equipment during lifts, carries, hangs, cables, or bodyweight work. Rowing machines are cardio machines that create a full-body pulling rhythm through a sliding seat, handle, resistance system, and monitor.
The difference matters because grip accessories support selected exercises, while a rowing machine creates a complete conditioning session. One may help a user hold a bar or handle better. The other supplies the movement, resistance, and cardio structure.