i have a solution to prevent the snake from getting stuck if the piece is meant strictly for aesthetics (decoration) stuff it good & full with dry floral foam broken apart into chunks. it comes in green & brown. dry floral foam is solid enough that it wont give if the snake tries to push in past it.
or use clay & just fill in all the cavities.
Exotic towing, you dont wanna wait til your snake has outgrown it before you get a chance to prevent him from getting stuck, cuz thats when you'll find out he's too big...when you have to rescue him from it.