There are two popular ways to launder bitcoin that this article doesn't really cover.

• Use a non KYC bridge to convert bitcoin to a privacy chain like monero, then when they want to use it, convert it to another currency like USDC. This effectively erases where the money came from and looks like clean money.
• Use a mixer which is a giant wallet shared by many people. Then the person laundering can send the cash directly from the wallet in small amounts when they want to use it.