I have a song on my 'to learn' wish list that could help - Hunch Gray:
It's on a 5 string, slap bass and there isn't a huge amount of ghost notes, but they are being incorporated in an active bassline. Nailing these ghost notes should get you well on your way to having a feel for adding speedy ghost notes.
It's a deep end approach though, there are easier, more structured (ultimately quicker?) paths. Still, I thought I would at least put it out there.
I linked to an example phrase, 1:57, with some semiquaver (quarter) ghost notes which is followed by a phrase with triplets (2:06), also incorporating ghost notes. Focussing on just those two phrases is sufficient for ghost note practice. I would add a third phrase and go from 1:57 to 2:22.