Thanks for the tip Alpha1. I figured I'd have to polish the finish once the final coat was applied. Based on the videos I've watched, it appears you can sometimes get away with very, very fine grit sandpaper, or even a clean piece of soft cotton!
Regardless, it would appear that for either Alclad or Spaz Stix you really need to start with a super-smooth basecoat of ultra-glossy black, followed by generous layers of the chroming product itself. It's been suggested that a good-quality enamel would work best. I've sprayed miniatures before, of course, but I'm concerned about just how thick the application here might have to be.
Anywho, I've seen the results some people were able to get on larger plastic models, and it's quite exciting to think something similar might be possible on a 'mech. Even if the effect destroys some of the illusion of 'scale', I think the visually-striking effect of a mirror-shiny mini (with a few ultra-saturated color highlights) would be worth it!