You can get stuff that LOOKS like astroturf at Home Depot or Lowes. And they sell reptile carpet. But I don't recommend any of it, because it's too hard to get poop out of it without scrubbing and scrubbing, and then it takes too long to dry, so you end up needing several pieces of it.
Good substrates can be thrown away when dirty. Aspen. Shredded paper. Paper towels. Newspaper. Cypress. I tried the reptile carpet thing way back around 1998 when I didn't know any better (long story). Threw it out. Then I got some green shelf liner stuff, which washed a lot better, and dried quicker, and if I had known about keeping the temps properly controlled Imhotep might have done fine with that.
But really, disposable substrate is so much easier. Spot clean, and when it looks nasty or it's been a month or so, dump & replace!