What a completely screwed up and incorrect description of the collodion process. Also, the result is infernally fragile.
That said, yeah, you can smear collodion on pretty much anythind dark and shiny and get some interesting results. Be careful, the stuff is borderline explosive, and most of the chemistry involved in the process is at least a little bit toxic.
Can you still get liquid emulsions in a can? You used to be able to get this crap that you could pretty much paint on anything and use with standard chemistry, I think. That's a bit more tractable, although it is a negative process, not a direct positive one like collodion.