My beardie's poo always smelled pretty bad - and he was perfectly healthy and fed a gourmet diet of silkworms, superworms, and a variety of healthy vegetables (staples being collard greens and mustard greens). I used sand for awhile, which helped a ton with the smell, but when I switched to paper towels, I'd get home to a room that reeked. To be honest, if I owned another *adult* beardie I'd put him on sand. I don't think sand is very dangerous for adult beardies as long as they are fed their insects outside the enclosure, and you use a veggie bowl with a high lip so they don't get sand in it. Also, I didn't use a water bowl because I would give my beardie his water out of an eyedropper, and also during baths.

That's my opinion of course; some people have said that sand causes a breeding ground for bacteria, because you are mostly spot cleaning it and doing full cleans is very difficult. However, I don't see how it can be more dangerous than spot cleaning any particulate substrate, especially if you use heat lamps and low humidity environments.

But yeah... if you use a substrate like paper towels/newspaper... pretty much always going to smell IMHO.