Hi Mate ,
I used 306's almost exclusively for a couple of years , cracking little drippers ,
did you just remove the wick with a pin or did you pull the whole bridge off
I always de wicked mine but on removing the bridge i found they did not hold enough liqiud and spat hot juice up the drip tip
if your still getting a burnt taste , soak it in a small glass of vodka overnight , remove it and blow it into a paper towell , gentle dry burn , prime with 3/4 drops of juice , top it up with a couple more after it's sat for a minute and you should be golden .