Filter patch bag for shroom growing

so i have a grow kit for shrooms. its the one where they give you the soil, rye grain, and spores. so far i have it growing well and i just got a few spore prints but idk where to buy filter patch bags. I'm thinking home depot or walmart will have them. if not i guess i'll stop by a gardening store maybe.

any help?

and if i get my 5 pound bag of rye seed covered in myecium(sp), will it make a difference how much soil i put it in? like if i were to put it in more soil would i get a greater yield?

thanks