Custom Molded Earphones

I’ve decided that earplugs are Og’s gift to motorcyclists. I’ve never ridden with my iPod, but I’m looking into getting some custom earphones. There are dozens of websites that sell custom earplugs, and at least one that markets itself as a modifier of existing earbuds. This site specifically says not to put the product in the ear canal, though, and I was under the impression that that’s where most of the sound was attenuated.

So, two questions, the first has a factual answer:

  1. Is using a regular molding kit in combination with a pair of regular earbuds safe?

  2. Has anybody here tried this (or used custom molded earphones that were marketed as such) , does it work, and how did you like it?