I wondered if it would give a jacket potato a bit of a buttery taste if you sprayed it directly on top. I sometimes put the olive oil one on some toast to make it a bit moister, but it doesn't really have a taste.
I've never seen the salad ones. I have a feeling that someone on here said only one supermarket stocked them at present and I have a feeling it was Morrisions, but I could be making that up?!