1/2" tape cleaner?

[Al Kossow]

 > The cleaner portion sometimes has an amazing looking mechanism I've
 > heard called "ruby blades".

AKA "Tape Scrapers"

Earliest cleaners used razor blades. Replace with harder materials 
later.

 > These can clean and burnish tapes in good
 > shape but can also ruin a tape in bad shape.

It sounds like what you have are bad tapes.
Why would you risk them on a certifier/cleaner?