While this is potentially a dirty laser, it's more likely to be a case of a bad blu-ray laser and it's not dirty, but rather failing. If you replace the drive, you'll void the warranty if it has any left but more then likely it's out. You can replace it using the guide here: PlayStation 3 BluRay Laser Replacement
The other thing that iFixit doesn't cover is you have to change the PCB, since the drive boards are married, which also means you need to get the correct drive so you can install the PCB. iFixit doesn't mention this for some reason. Unless we know which PS3 you have, we can't figure out what drive you need.
If you go the Sony route, it's $150, you'll get a refurbished exchange system and lose your save data. Sony will not preserve your data, but I think you get a 90 day warranty too. This is only if you can afford to lose the data and $150 is viable for you.