Analysis of Comb Sort?
The $\Omega(n^2)$ worst-case lower bound of Comb sort (or Dobosiewicz sort) has also been proved using the incompressibility method based on Kolmogorov complexity. See for example the survey by Vitanyi, page 16. If you are also interested in the average-case lower bound on the running time, the paper gives that as well. Moreover the proofs obtained with the method are natural, easy-to-follow and usually quite short.