I flossed mine once a few months ago and it has not needed it since-- which is pretty good for me. As far as the poster putty in the head-- doesn't seem to affect muting at all.
This morning I tried the flossing but apart from the fact I'm not sure if my floss is the waxed kind, I found it extremely difficult to do and I had the impression it was not doing anything.
So I decided to try the soap method for now, until I get a waxed floss and try again.
As for the tack in the head for muffling purposes, after a lot of extensive testing, I realized it is just very difficult to place the little ball in the right place, but once you're able to do it you can obtain a rather satisfying compromise between overall volume and nice sound.
But given it is so difficult I just ended up applying the tack flat like a tape and once placed that way it does just the same as the tape, but without the gluey stickiness once it is removed. The tape is easier to place and not prone to be accidentally altered when handling the whistle but can be sticky once removed, the tack is harder to place and need a little more care in handling but doesn't stick.
In the end both the tape and the tack give the same results sound-wise, and both have their advantages and disadvantages in getting applied and removed so it is just a matter of what one prefers. I think I'll just use the tape for now.
Are you playing Italian folk songs on your whistle? How do your friends and family like the whistle?
Family and friends are not affected that much by my playing, neighbors are to some extent but I as I said I try to play it quietly (tape muffling) and hopefully I won't have to listen to any (rightful) complaint.
I am a quite person, I listen to music and tv at reasonable (even lower than that) volumes and so I play the whistle. Of course once I'll start to play it better I'll un-muffle it and I'll see how people around me will react.
For now I mostly do scales and a few simple tunes that are on the leaflet that was in the whistle package (like auld lang syne, danny boy, on top of old smokey etc.), I'm concentrating mostly on the finger movements.
So no Italian folk songs for now just the ones I have at hand in the leaflet and a few I'm trying to reconstruct by hear (Ireland's call and flower of Scotland namely), but I'm far.
I also don't even know if the "learn by playing tunes" is the right way to do it, or at least if it is right for me. I have little or no musical background and I wouldn't want to learn the whistle this way, I would like to learn and read the music which will be also useful should I ever want to learn to play another instrument.
I'm currently looking around for lessons and tutorials but from what I could see they are mostly just "learn by playing tunes" which I guess is fine but, I don't know, I don't "feel" it is right.
Right now my main concern is just finding more time to devote to the whistle among other activities that take my spare time away.
But I'm digressing here.