i don't really know what you're talking about
isn't the f-smash what you want to do?
Soorry, I suck at explaining things.
You know how the Hydro Fsmash has you use the Z button and the C-stick together while shellshifting?
Merely when I was learning that, when I would mess up on the Hydro F-smash I would do the Hydro grab because the difference is mainly timing of when you hit the buttons and at what angle you hit the C-stick at.
Ex: Run right, go into shellshift animation as you change your direction, right as you are in the coming-out-of-the-shell animation of the shell shift you simply hit Z+Cstick left to do the Hydro Fsmash.
When I mess up on that and accidentally hit the C-stick down at a 45 degree angle I do a Hydro grab. I remember that the way I did it was simpler than how the AT thread explained it.