It's a Sony conspiracy!

they would rarely ever completely fail on you like the RROD or E74 for the 360, but they do freeze a lot while you use it.

Mostly depends on the type of software and game data. I've noticed with the latest update of Mirror's Edge my PS3 froze a few times, while before the update I didn't have any issues of freezing. Happens only with an occasional game, like it happened on the PS2 as well, *remembers the horror of the very first Japanese Star Ocean till the End of Time release which made the PS2 froze like 20 times*.

Ylod. But Ylod doesn't cause games to freeze.

freeze it's random.
LBP used to freeze , now it doesn't happen.

Does anyone know if there is a proper disc cleaner for the PS3?

Ylod is not like RROD.Its a sign of overheating.

I got it once,I just stopped playing for 3 hours and then started it again and my PS3 worked.

yeah thats what you had to do, if you turned it on just after that, may have burned.