As I understand it, they're talking about "bog steel", or what the Celts used to make before they could make crucible steels.
Basicaly it's iron heated real hot over a smokey fire so it can absord some of the carbon.
It's more involved than that, but you get the idea, and I don't have the specifics.
Is it any better than "dead" steel? I'll put it to you this way, it was a manufacturing process that was abandoned in favor of crucible steels by people who loved their swords.
Besides, if it's Angel Sword you're talking about, it's a ripoff. No weapon is worth as much as they charge, I don't care who made it or what they claim. Some colector *might* be willing to shell out the dough for an antique though.