You can use organic top soil or just plain dirt too, if you have too. Also just pick out what waste you can see and simply keep cleaning it that way. I have some orchid bark in my biggest tort table that is over 5 years old. I never throw any out, I clean it by hand and if I empty out a habitat I pour boiling hot water over it, allow it to dry, put it into a plastic bag and put it away. I live in the PNW and it's just too hard to find here. When I drive down to my sister's I load up on the stuff. I get so much I can feel the weight of it in my small car. But I don't ever waste it and so far my routine has worked pretty good for me...