Jelq timing

I’ve often read that you guys use to do 2-3 second lasting jelqing. My single milking last only 0.5 seconds. I become unconcentred and my unit tends to get flaccid if i try to do 2-3 second jelq. Does the 0.5 jelq works, or should i do 2-3s?

Thanks

Do at least a 2 second stroke, 0.5 seconds is masturbation. Maybe grip harder??