Question about my Tarot deck

I am a beginner with tarot. My brother used my tarot deck for himself, to do a reading. I didn’t know that he did this, he didn’t ask.. but I have heard that you shouldn’t use another persons deck. What are thoughts about this? If so, how do I reset or cleanse the deck? Is this necessary? I read waiting for a full moon and to place a clear crystal on the deck. Any thoughts would be appreciated!