Most water heater elements are a loop of nichrome wire encased in some kind of high temp sand.
Low voltage elements could be made in a similar way if you can cut the loop off the end, spot weld the nichrome to the inside of the tube and then cap the tube. this would divide the resistance in fourths, which gets you somewhere at least.
alternatively you can replace the coil of nichrome with a single straight rod of nichrome using the same topology.
alternatively, shake the sand out, and pull half the nichrome out, then refill with sand. yep, that's a lot of work and you'll need a pretty agressive vibrator to shake the sand back down the tube, while holding the nichrome under tension.