Well, click castsequences are gone.
So you could not have an exact copy of the guide, tweaked to your spam speed.

The basic mechanic is to use Nature spells, until you move the bar one way.
Which gets you a bonus with your Arcane spells, at which point you spam those until the bar moves the other way.



As naPS said, you'd probably be better off with a macro which will take you all the way one way, then all the way the other.
And just go with the macro.

Alternatively, go with two macros (castsequences) one for Arcane and the other for Nature.
And then use the toggle to switch between them.

You could use the same approach for Trash vs Boss sequences or whatever.