Perhaps if you referenced something concrete there would be more to talk about?

I'm only aware of Bosch, which uses some type of humidity-absorbing crystals that then desiccate with the heat of the next cycle. The marketing implication that this doesn't use energy would seem to be playing on that lack of understanding of thermodynamics.

Never mind costing 2x or more for the models with this feature, still seeing complaints of people online saying they don't get the dishes dry, combined with the all-too-common refrain that you have to use "rise aid" - ie elective chemical residue.

(I edited my original comment to focus on the failure of functionality over the lack of a specific mechanism)