I'd heard some folks complaining about the off taste on a new head, so I always rinse my new heads in hot hot water before the first time I use them, and I've never had any off flavor.
There is an issue with flavor muting. I've found this decreases as the head gets broken in. I think maybe the wicks get softer and spread out more, but I have no idea really. I tried unbraiding the wicks, and I was pretty stoked at first, as the flavor did seem to improve some. But I rinse and dry burn every couple of days, and those unbraided wicks start to break off and degrade *really* quickly. I ended up replacing that head in a week because I was afraid of inhaling wick particles. Maybe I did it wrong?
I saw a minor mod where the poster rolled up a thin strip of cotton (think toothpick sized) made from sterile rolled cotton from the drugstore and laid it over the top of the coil, and cut tiny notches in the bottom of the cap so that it wouldn't be choked off. It was reported to increase flavor. I tried this with some cotton I had, but I could taste the cotton. I was thinking of getting some cotton wick, boiling it a few times, and trying again with a piece of that. I don't really want to rewick with cotton, because I like to dry burn it to clean it, but a replaceable overwick would be cool, if it does help.
