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.