So my kids want to make a hide for my BP that's coming next week and I really don't feel like spending $20 on a bag of rocks from the pet store.. I had them collect a bucket of different sized rocks from the backyard that I had dumped for my driveway... If I spray them off really good and soak them in bleach would they be okay to silicone to a plastic bowl or Tupperware to make a cool looking hide..