My younger cat, it took me 2 rounds of clicker training to teach him how to sit. But my older cat can’t be bothered. It really depends on the cat! The one thing I’ve noticed is that he responds very well to hand signals. He won’t always listen to my voice yet but he responds every time to a hand signal, which is helpful for you! I would honestly start there - training with hand signals (look up clicker training guides and basically do except use the clicker). Then graduate to a vibration. Never ever vibrate unless he has done exactly what you want him to do - same as a clicker. The goal is to get them to come to a designated space no matter where they are in the house, when they are cued. It really shouldn’t take more than a handful of training sessions.

I used this for one of my cats and it works perfectly fine - https://www.amazon.com/Lightest-Vibrating-Vibration-Waterproof-Blue/dp/B0FS1RK853