Handcannon is correct, there are many different ways to Finnish your calls. I like the glossy, I use DEFT CLEAR WOOD FINNISH the brush on type. however i do not use a brush or sponge, I use a small air brush it works great gives a good even coat. you can also get it in a aerosol spary. some hunters don't like glossy for fear of the glare but your hand covers the call when in use. i also use deft sanding sealer, i use a 100 grit paper on the lathe then a 220 grit to finish it, with some hand sanding after first coat.
good luck, and show us you call when you Finnish.
gary