Growler Filling Techniques

Can anyone recommend the best ways to fill a growler from a keg? My technique is simple enough, but I keep getting beers that are nearly flat just a few days after filling. I know an open growler is a time bomb, but shouldn't the carbonation last if it's kept closed?

Here's how I've been doing it:

That's a big drop, do you have foaming problems during filling? Is that what the pot and towel are for?

I usually fill growlers by slipping a short section of hose into the faucet (just long enough to reach the bottom of the growler). If it's a beer with higher carb levels, I'll back the keg pressure down to ~6lb or so, just enough to push it out of the keg. I don't think I've ever had beer in a growler for more than a day, though, so I'm not sure if it stays carbed for longer than that. Usually once I've moved the beer into a growler, it's hours, not days, before it goes down the hatch

i think it maybe is a day or two at the max before i drink anything filled in a growler.
However, all i do on mine is toss the growler in the freezer for an hour or two, if there is still foaming issues, i turn down the pressure a bit and it's golden.

Get and extra line with a picnic tap is what I have and I never have n e foam issues, something about what you are doing looks like a PITA.

I keep a keg full of sanitizer to clean it out and when I hook it back up I push out the sanitizer into something else and then fill the growler.

I chill my growler, disconnect my gas, pour half a pint into a glass and then proceed to fill my growler.

I just tip the growler up the the tap and fill 'er up like I would pull a pint. Like Wilconrad, I sometimes need to back the pressure off, but usually just leave everything the same.

I take a. Title filling wand and attach it to the picnic tap. Bleed much of the presuure from the keg, then fill.

Looks like you are using a tube with a pretty wide diameter (1/2in). I have one of those SS perlick attachments and use the typical 3/8th vinyl tube. I also turn down the co2 a bit. I don't get much foam at all. With a rubber stopper growler, the carbonation lasts as long as a bottle would... Indefinitely. It also helps to chill your growler. Cold will help keep CO2 in solution.