hi. i keep indonesian species (salvator) and do not use dirt anymore, what so ever. i do use leaves which the lizards readily accept for foraging, burrowing, and nesting. these leaves are collected off the ground (raked up), and added generously to the cage floor ( up to 2 feet thick, and a few hundred pounds when concidering the lower layers are wetter. by adding wood logs to the surface of the leaves, it compresses them down making a compact floor rather than leaf quicksand. i have an army of wood lice ("roly polies", millipedes, and others) which co exist in the substrate and help by breaking down the leaves, excrement, and rotting organics. these bugs were collected along with the leaves and wood without trying. the only smell in the cage is leaves, and thats a hell of a lot better than if i continued using cypress, or other woody chips. i would never concider baking, microwaving, or altering these leaves, or naturally collected wood. i do not collect from pesticide sprayed land. much of the habitat our indo species (salvator, dumerili, rudicollis) come from are leaf littered forest floor (*do a google search for varanus salvator or rudicollis and see pics taken in wild- most are seen on the forest floor). they nuzzle through the leaves for food. this encourages their natural feeding behaviors, exersise, retreat, and stimulation. the substrates such as peat and cypress are too dusty and dry out quickly. wind up with sneezing lizards. dirt can be used with leaves, and some here do use this combo. i can only suggest to you to try a leafy substrate. i think your rudi would benefit big time. -john a
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