I've used nothing but picnic taps for 20 years. To bottle, I put a piece of tubing through a one hole #2 (maybe 2 1/2) stopper. The diameter of the tubing is such that it fits inside one of the picnic taps, and and it's long enough to reach the bottom of the bottle while sticking up a few inches above the stopper. I unscrew a QD from one of my CO lines and use that line to purge the bottle. I put the end of the tubing into a picnic tap and seat the stopper in the bottle. I open the picnic tap and the bottle fils about 1/3 of the way before back pressure stops the flow. I then use my thumb to gently crack the stopper just a bit, so the flow starts again. When the bottle is full, I close the picnic tap, remove the stopper and cap. Easy, cheap, and effective.
I do it this way, too. It works great, doesn't cost much, and is easy to clean. I keep a wallpaper tray nearby to set the filling assembly in while I cap the bottles. I use a Vinator Bottle Rinser with Star San just before filling each bottle and drop the caps in there to sanitize, too. Any of the methods will foam less if you can get the bottles and equipment good and cold before filling.
This is too clever for words. I haven't bottled anything in ages, but have no desire to mess with my old counterpressure rig ever again. I was thinking, how could I do this, given that I have only one keg at a time on tap in my keezer and thus only one gas line? Then I realized: if I put a "tee" on the gas (recycled from CP rig,) and send one leg to the keg, I could put a second picnic tap on the other gas leg and use that to "purge"*
the bottles. And it gets better. I have a ball lock adapter for my Intertap faucet. Running the liquid picnic tap off the regular draught line would add considerable restriction, further reducing foaming. This would be just easy enough to set up and clean that I might not mind filling the odd sixer. *
Put that in quotes lest I invite a lesson on gas laws, TPO etc.