Honest answer is that we cannot say whether or not the drive will or will not read bootable media after being cleaned, if you try the device with a game or a video and it works ok it suggests that the drive does not like the ISOs or the disks that the ISOs have been burned to, were the ISOs all burned to the same brand of disk.
JFYI: it is not uncommon for only one laser on an optical drive to fail, this can result in it failing to burn, be unable to read either a DVD or a CD or it will play one but not the other.
RE cleaning the drive, optical drives are relatively cheap to purchase and you can if you are not careful pay more for a DVD/CD cleaning kit than it would cost for a new drive, example drive here DVD cleaning kit here