My definition of raking is different though.
A rake is when you hit one note only, preferably on a high string. But before you hit the note you hit the strings above it muted. Its mainly used to accentuate the note you will hit clean.
so for example, I am going to hit an A on the 5th fret of the high E string. This note will be held by my ring finger. Instead of just picking the note, I mute all the strings at the fourth fret by lightly touching them with my left hand's index finger. Then, just whack with your right hand
It'll sound like 'krck krck krck' then the note. This is what a rake is to me, dunno if my explanation was clear enough though, let me know if there's another definition to this technique??
Personally, I sweep the G, C and E major and minor chord shapes. I'm sure you know how to play these chords barred, so just sweep em. remember to lift ur fingers after hitting the note to mute em.
Don't hesitate to 'barre' if ur sweeping on the same fret on different strings (mainly on the A major shape). I used to play everything with a different finger, but I find it much easier to just roll it. It feels funny and probably isn't too clean, but its faster and easier.
As with all speed-related guitar tricks, start slow with a metronome till you're clean and comfortable with it, then slowly up the metronome's bpm.
Hope i've helped! :wink: