Updating won't "unhack" anything. The only thing it will remove is CIOSCORP and preloader and any system menu themes if you installed any of those. Your HBC, installed wads, backup launcher, cIOS will all still be intact. Deleting those things through data management will not get rid of the tickets the channels install on the Wii so you would need to remove your channels with wad manager using the same wads you used to install them to begin with (DON'T UNINSTALL ANY IOS'S YOU INSTALLED THROUGH THIS, ONLY VC GAMES AND CHANNELS). To remove your cIOS I think there is an app called cIOS uninstaller, or you can use anytitledeleter to delete IOS249 (and ONLY that IOS, NOTHING ELSE). The HBC of course should be the last thing you remove and if you don't have the wad for it, then you need to use anytitledeleter to remove the HAXX ticket.
That should pretty much remove anything you did. Though I don't really suggest it as there really aren't many good reasons to "unhack" a Wii, and not really knowing exactly what you're doing to do it is the biggest brick risk you can take.