Here some additional information on the subject.
We removed that method as it encourages bad practice. Since SiteMap nodes are dependent on so many things and flushing the entire cache too often makes it very inefficient. In most cases you should not need to take care of this as Sitefinity places appropriate cache dependencies for every cached node. This way only affected nodes will expire. The appropriate way of adding additional logic for node expiration is with custom cache dependencies. Unfortunately, working with custom cache dependencies is not documented yet.
In case you really need to flush the entire sitemap cache you can do it like this:
the Telerik team
Thank you for being the most amazing .NET community! Your unfailing support is what helps us charge forward!
We'd appreciate your vote for Telerik in this year's DevProConnections Awards. We are competing in mind-blowing 20 categories and every vote counts! VOTE for Telerik NOW >>