Is this in reference to a specific post? I agree that no product can fill a scratch, as was previously said, but polishing does in effect remove scratches by reducing the surrounding surface to the same level as the scratch. You aren’t forced to bring the entire Holofoil section down to the level of the deepest recession, either, the image of the featured Pokémon can be quite fragile in terms of resilience to polishing.
Check this video out:
The immediate tell that the card was polished is the level of holofoil reflection.
That’s Kurt himself polishing a card with his solution, haha. Pokémon cards are resistant to skin oils and you will not see a result like that ^ just wiping your Hitmonchan down the way that any other person would (if they weren’t trying to scam). Humidity treatment is a bad idea as well, but IMHO it’s all equal behaviour and there’s no hierarchy in terms of card altering. That includes recolouring, too.
You’re either cleaning debris, as we have both said, or you’re altering. Kurt’s cream is an abrasive.