I've had good results with a similar method to the one listed in that link - on an inkjet printer with both white and clear decal paper. The clear is of course a touch easier to use but you can't use it if you're trying to do a light symbol on a dark background, which is where the white paper came in. I used both kinds because I was doing models from different companies of Salamanders (e.g. 3rd company orange symbol on black background, 5th company is the reverse), and I was also preparing chapter symbols from a whole bunch of named-but-obscure chapters to use for my Deathwatch marines.
So, both the clear and the white worked and worked well, thought the clear was easier. It was a bit of a pain using an inkjet printer trying to get the right amount of spray varnish on them so that the ink doesn't run when you apply them but at the same time they're not too stiff to conform to a curved surface. From that point of view it would be easier to use laserjet decal paper, since it doesn't need sealing. The largest amount of work in the whole job was just finding all the different symbols I wanted to use and copying them into my print file with the right size and the right background for the white paper ones.