If you want to regularly update the site yourself, make sure that your wallet, which owns the Walrus Site object, is active. However, if you want updates to happen without constantly doing it yourself, the aforementioned smart contract approach is a good route.

When you deploy a website on Walrus, a Sui object representing the site is minted to you as the deployer. Ownership of this object gives you the ability to update the site. To allow a group or a third party to update it, you can implement smart contract logic to manage the ownership of the site object. This means you would write a smart contract that specifies rules on how the object can be transferred or updated. Setting this up could evolve into a useful infrastructure application for Walrus developers.