Unnecessary suffering? It does matter how one dies. I know it's from Wikipedia, but this is a useful quote...
"Napalm is the most terrible pain you can imagine," said Kim Phúc, a napalm bombing survivor known from a famous Vietnam War photograph. "Water boils at 100 degrees Celsius (212°F). Napalm generates temperatures of 800 to 1,200 degrees Celsius (1,500-2,200°F)."
I'd prefer something quicker.
As for its use in rockets, no, but newer, similar substances are...
Triethylaluminium thickened with polyisobutylene is used as an incendiary weapon, as a pyrophoric alternative to napalm, e.g. in the M74 rockets for the M202A1 launchers. In this application it is known as TPA, for thickened pyrotechnic agent or thickened pyrophoric agent.
By the way, can you resize the photo there, Hempy, so we can all still read the page?