is there then an alternative to glow plugs that no one seems to be using?
Well, there are electrics, and there are gassers. Given the start of the topic, I beleive electrics need no description. Gassers are helicopters about the size of a 90 sized glow heli or bigger that run on gasoline and oil mix. Similar to what you would feed your chainsaw, or weedeater. Similar engine too.
Rafael