My views on cleaning are a bit extreme compared to most (read more here). Given that, I would recommend to not alter your cards, especially if you plan to grade or sell them in the future.
For context, this is how I define cleaning vs. altering:
I view any restorative procedure as altering the card and immoral if not disclosed.
Cleaning [- i.e., the integrity of the card is not changed and chemicals are not added]
- Using small amounts of water to clean a card
- De-warping a humidity-induced cupped card
Altering [- i.e., restorative procedures]
- Adding substances to the card’s surface for polishing
- Buffing out scratches
- Flattening cards to remove indentations
- Pushing a slightly raised corner or edge downward
- Recoloring
- Removing ink from a signature
- Restoring cardstock
- Trimming edges/corners