I strongly recommend Organic Top Soil as a primary bedding!  Usually Scott's Or EarthGro Brand is best. However, there are other options such as the following:
a:) Orchid Bark

b.) Sand Soil Mix

c.) Eucalyptus Mulch

d.) Repti-Bark

e.) Eco-Earth

f. ) Pure Cypress Mulch, not the "blend".

   Keep in mind that constant cleaning of any type of substrate is required to assure the health and well-being of your Tegu.