Most places that use multiple decks change the cards once a day, either when the table opens for the day, or if the table never closes;on Graveyard shift, when it's slow. Find out when they change them and make it a point to be there. I believe that you'll find that they DO fan the cards for all to see. I've only known ONE casino in my 35 years of playing that DIDN'T do this, and I played enough shoes in THAT place to be virtually certain that THEY didn't cheat anyway.
If you ARE correct and you HAVE found a casino that never shows the cards, that STILL doesn't mean much. Stand back and count down about 50 shoes, then average out the count at the end of the shoes. If you CONSISTENTLY get extremely high counts after a MINIMUM of 50 shoes, then and only then you MIGHT have something to worry about.
Personally, I think you're wasting your time even thinking about this. Even the Indian casinos all have some sort of gaming board that oversees the operations. To think that they would risk it all on such a small gain is almost ludicrous.