How can I mix the BNB in my wallet?

Yes, you can achieve this through a mixer. However, the official Tornado Cash website has been shut down by the U.S. Treasury Department. You can still perform mixing by directly interacting with Tornado Cash’s smart contracts.

If you don’t know how to use the contracts yourself, you can use PandaTool’s mixer, which is built on top of Tornado Cash:
👉 https://tornado.pandatool.org/