craftgrrl | :) a lil help please :)

I'm thinking of making THESE for my mom for x-mas. The problem is, she doesn't like to wear slippers that don't have the non-skid stuff on the bottom, know what i mean. at 3:30am the actual name of the stuff escapes me but it's so you don't slip and fall in your slippers.

does anyone know where i could buy something like that?
i wouldn't even know where to look because i've never made slippers before. depending on how fast i can churn them out, EVERYONE might be getting slippers this year! hahaha

thanks in advance

(x-posted in