Perhaps I'm lucky but I have not had a verification failure since I went over to branded media.
However, to answer your question, If I had a failure in the past, I simply read the disk in a 'read only' drive. If this worked I considered the disk 'useable'.
It must be worth my saying that I also used only branded media that passed verification for any important data that was not to be kept on a HDD in some form. I treat all disks as potential 'failures' in one way or the other and for irreplaceable data, photos, home videos and such I make two verified copies which are kept in separate locations; one of these I treat as a 'master' and never use.