Yes, I have used that method to great effect! However I bought myself a growler filler earlier this year (basically a silicone tube with a fitting that goes in the tap) that works just as well, as long as I purge some of the co2 off the keg first. Otherwise I'm dumping tons of foam. As long as I cap on foam I don't lose much carbonation. I even bought a fancy (not beergun fancy, but amazon fancy) bottle filler 2 years ago that got used once, because its a PITA to put together. *Edit forgot to add, it works on the same principle as the one outlined in the thread, except you have to hook up co2 to it. That's why PITA.