It's a subtle distinction. Argument in the alternative considers multiple different possibilities as hypotheticals in order to rule them all out, but isn't that kind of what kettle logic does as well? Can a kettle logic argument be easily rephrased into an argument in the alternative?
I feel like there's a difference between them that's more than just whether the argument is true/valid or not, but I can't quite put it into words.
[1] https://en.wikipedia.org/wiki/Argument_in_the_alternative