The Clear-Site-Data header tells the client browser to delete browsing data for the origin/domain. The accepted directives are cache, cookies, storage, executionContexts or * (wildcard), e.g.:

Clear-Site-Data: "cookies"
Clear-Site-Data: "cache", "storage"
Clear-Site-Data: "*"

The downside is that this is still an experimental and unstandardized feature which works only on recent versions of Chrome/Firefox. More information can be found on MDN.