Why should I clear “Unknown Tokens”?
Although it is generally obscured behind a single fee displayed to you by dApps, there is actually a cost (a.k.a “rent”) to opening and keeping open each token account: 0.00203928 SOL. This sum is paid by you and is locked in the account as long as it exists. Closing the accounts is the only way to get them SOL back!
Wallets can get cluttered fast, especially if you regularly buy/sell NFTs. A tidy wallet can prevent mistakes.
The answer above comes directly from the dRaffle Website
DISCLAIMER
Use at your own risk
Can interfere with defi tokens that are not registered.
1. Navigate over to dRaffle
2. Make sure the “Wallet Cleanup Tool” is selected.

3. Connect the wallet that you want to clear of “Unknown Tokens”.

4. Now select the “Unknown Tokens” you want to close or choose the “Close All In One Click” button.
5. Enjoy your clean wallet & your refunded Sol!