Are you sure you can do all B tech without the C stick? If you hold forward on the movement stick and flick back on the C-stick, you can gain side B momentum in the direction you C-sticked without changing direction. How can you do that without the C-stick, since it only works when you are essentially inputting two different directional inputs simultaneously? Trela does this sometimes.
Yes I am 100% since I can do it and I don't use the B-Sticking.
There are 3 basic "B" techs. I'll try to teach all about them.
Reverse B/Turn Around B: Turn around and perform a special move while maintaining the same momentum you had.
On most characters works on: Anything but Side-B
On Mewtwo works on: Only Neutral B
Input: While moving a certain direction quickly flick your control stick towards the opposite direction and return it to neutral then as quickly as possible input your desired Special move.
B-Reversal/B-Reverse (yea I know the name can be confusing with the first tech): Turn both your character and your momentum around while performing a special move.
On most characters works on: Everything but Up-B
On Mewtwo works on: Side-B and Neutral-B
Input: While moving a certain direction perform your desired special move (if it's side-special then input it in the same direction you're currently heading) and INSTANTLY AFTER flick the control stick towards the opposite direction you're headed. If timed correctly then you should reverse both your facing and your momentum completely.
Wavebouncing: Turn your momentum around while performing a special in the same direction you were facing (This is the one you're referencing in your post).
On most characters works on: Everything but Up-B
On Mewtwo works on: Side-B and Neutral-B
Input: Input both a Reverse-B and a B-Reversal. While moving in a certain direction flick the control stick in the opposite direction and return it to neutral. Then quickly input the Special move (if it's Side-Special you must input it in the opposite direction you're heading) and then instantly after flick the control stick in the direction you were already heading. If done correctly your character will perform a special move forwards but will completely reverse his momentum in the air.
Note: Remember to start holding the opposite direction you were originally headed torwards after performing the tech in order to actually accomplish the momentum transfer.
Basically in order to do Side-B if you're heading left your input should be:
1-) Hold left direction on control stick
2-) Side-B torwards the right
3-) Instantly flick your control stick to the left
4-) Hold right direction on control stick
Neutral-B:
1-) Hold left direction on control stick
2-) Flick your control stick to the right and return it to neutral
3-) Press B
4-) Instantly flick your control stick to the left
5-) Hold right direction on control stick
Hope this small guide helps. Wavebouncing is the only one I find hard to do and only for Down-B and Neutral-B, it is actually quite easy to do for Side-B. Since Mewtwo cannot do any "B tech" for Disable, this means that the only "hard" one is Neutral-B which B-Sticking doesn't help with anyways.
So in conclusion I think it's quite easy to learn to do what B-Sticking has to offer with just regular old control stick controls.
Another thing to note is that for Side-B, B-Reversal and Wavebouncing are actually the exact same input, so it makes it much easier to learn. The only difference is the direction you input.
On B-Reversal it's more natural since you input the direction you're currently heading and then just flick torwards where you want to go. This makes it so you only have to change directions once in the whole tech (the flick which also transfers the momentun).
On Wavebouncing it's the opposite, you input the opposite direction you're heading and flick torwards where you don't want to go (torwards where you are heading). This means that you need to switch directions 3 times (first to input, then to flick, then to transfer the momentum), which is what makes it "more complicated" even though it's the same input.