As an anti-slip technique, they dust the middle finger to the forefinger, or from an annular finger to a forefinger and a thumb tip with 'giriko rosin powder' (pine resin is boiled down, dried and broken into powdered state) and make it fit in.
滑り止めに「ギリ粉（ぎりこ：松脂を煮詰めて乾燥、粉末状に砕いたもの）」を中指〜人指し指、或は薬指〜人指し指と親指先にまぶし、馴染ませて使用する。