If you'd like to keep the assets in your database for future reference (and not delete them), you can't fully hide them, not even with the "don't show" option. If you set an asset's state to something other than "active", as you've done, the asset will be excluded from *most* reports, e.g. reports found in the Reports tab. As you still need to be able to view it when necessary, the asset isn't removed from all pages. You can still search for it for instance and see it when you click the Assets link at the top of the console. Where the asset is displayed, it should be "grayed out" though, indicating that it's not set to "active".