I was a thumb-sucker. Big time. I didn't quit the habit until I was 12'ish. I can't really recall what made me finally "just say no". I'm pretty sure I just grew out of it (took long enough). I remember being at slumber parties and working some strategy to lay at the end of the row of sleeping bags so I could be hidden. If I was between two friends, I had no protection!
I saw this silly "Thumb Sucker" and, while it's not being marketing as a tool to curb thumb-sucking, it got me thinking about all the things my parents tried on me. Tabasco, vanilla, band-aids... threats of me having to get a part-time job to pay for braces (praise the Lord for child-labor laws!).