The fact that you even consider putting fish in to see if they live or not states that fish keeping isn't for you... You should do everything you can to ensure that FISH DON'T DIE! Causing an animal to suffer needlessly (even if you think 6 hours isn't long) is just down right cruel. Asking that question means you obviously can't tell the difference between right and wrong with regards to fish welfare.
Yes, it's frustrating having an empty tank while you're doing a fishless cycle, but don't you think it's worth it when you have a tank full of healthy happy fish at the end?
You can make it quicker by getting some mature filter media (I did that and my tank was cycled in 2 weeks), by either getting some off a friend or asking on here for someone in your area to donate.
Seriously, your LFS will keep advising you to buy fish, knowing that if they die they can sell you more fish. And it's not just fish, they can reccommend this product and that product to try to combat the unknown problem... do you really have money to throw down the drain like that?
if you have bought aquarium specific gravel, then I'm pretty sure, so long as you rinsed it, that it is not the cause of your problem. The rock you got would only pose a problem if it was for a salt water tank (or not for an aquarium at all).
Get yourself a bottle of pure ammonia (make sure on the bottle it states ammonia and water ONLY as ingredients), use the calculator in the beginners section list as to how much to add to your aquarium. Post your water test results on here so we can guide you, and just have patience.
People on here are nice and friendly, and will help you in any way they can, but coming onto a site full of fish lovers, and stating that you're willing to keep risking fish's lives is not a way to gain help and support.
Also, while your tank is cycling, you can research what type of fish you want, and get help and advice on stocking levels.