He is most likely just telling you the truth. even those beddings that are advertised as being able to be digested can cause serious problems for reptiles if ingested.
i currently dont have any reptiles. thinking of getting a Centralian Carpet Python also know as Bredli's Python (Morelia bredli). anyway.. i doubt i have any pics anywhere of any of my previous setups.
here is a link to a couple setups. Some good reading there.
CLICK ME There is two setups in this one. The first has pictures. I dont care for the substrate he used in the first setup. I have used it before without problems. Although I removed it after a short time do to the fact that I was worried about ingestion and cleanliness. This is one of the substrates that is said to not cause problems if ingested. The simple truth is that anything if ingested in the right amounts can cause impaction.
One thing he points out that I really want to make known here is this:"Keep in mind that you don't want the substrate WET, this will cause scale rot and possible respiratory infection." This is also true for not just the substrate but the entire enclosure. Mouth rot, scale rot, and respiratory problems are common in reptiles that their owners have kept too moist. 60 percent humidity is all you want in the enclosure. Along with a bowl that the snake can easily submerge their entire body in.
The second setup described in this link uses "Repti-Turf" style substrate. Its like a outdoor carpet. This is the style substrate that I personally use most. Can be easy to clean and sterilize. Although it like any substrate should be inspected often. If it starts to get worn and fray get rid of it. Same hold true if it start to stink or become overly soiled. Also a "UTH" is a "Under the Tank Heater".
The forum these are from can be a great source on good info on these snakes.
Oh can't remember if I mentioned it or if it was mentioned in the links(most likely). You want to provide a hide area for the snake to comfortably rest in on both the warm and cool end on the enclosure. Also they use the ole "length of enclosure + width of enclosure= the length of the snake". I always liked to have the length of the enclosure to be no shorter then the length of the snake but thats just me. OK that should be enough for now. hollar if you have any other questions. The other thread that Evan started should have a good bit of info there for general husbandry. Although you should read and learn as much as you can. Feeding with "Python Regius" aka, "Ball Python" aka, "Royal Python" can be a royal pain should yours decide to not feed. That was covered a little in the thread Evan started that I mentioned earlier.
Also her is a link that goes thru all common substrates and gives info about they and pros vrs cons about them. you can check it. http://www.repvet.co.za/herp_substrates.php#Carpet
OH! I am sure it has been mentioned already somewhere but... you will want to change the snakes water daily or anytime it gets dirty. Which ever comes first.
Hope I didn't lose ya.
Later,
jay