Reverse rake?

Whats a reverse rake?

Blues Shredder

Using your fingers to 'rake' the strings? As far as bass is concerned, 'raking' usually means you use your fingers to strum the strings. I s'pose that a reverse rake means you work from the high strings to the low strings. I may be wrong though.

I am supposed to do it with a pick

Blues Shredder

I thought raking is the technique by touching the strings one way, no alternate picking, with a pick. A kind of arpeggio. String after string.
You can do it from low to high and high to low , i guess the last is called reverse rake.
I find it a difficult technique, especilly to build up speed.