Devil's advocate here. In what scenario would I want to use this?
As said: It deleted 310 tickets on a Wii U. The Wii U still works fine, all titles start just like before. So these 310 tickets where just garbage collected over years of usage.
I'm not sure where all these garbage ticket come from but I think the chance of collecting garbage is the higher the more titles you install from differrent sources (like download a game with FunkiiU, install it, now download the same game with Wii U USB helper and install it, too: You have two tickets for just one game as the tickets differ slightly).
Not only losboy/Godreborn, it can also work in another scenario, you try to download a game with Nusspli and there's a bug, so it can correct this type of pb I suppose, it's kinda rare, but also healthy for a wiiU.
Yes, it fixes such issues, too, but to be fair this shouldn't be needed anymore: NUSspli uninstalls a title before installing (to allow homebrew channel updates with ease) and (since version 1.125) it deletes the corresponding tickets, too.
As if this wouldn't be enough: Since NUSspli 1.125 it will even try to detect and correct broken tickets before installation.
So in case you have something with a broken ticket installed just install it again with newest NUSspli version and all should work...
//EDIT: And yes, the ticket cleaner uses codes and experiences from NUSspli: NUSspli was able to delete tickets before the cleaner existed.
//EDIT²: In case you reinstall a title with newest NUSspli but this does not fix the issue NUSspli wasn't able to correctly identify the broken ticket. No need to redownload through: Just delete the title.tik file from the download folder and use NUSsplis "create a fake <titke.tik> file" option, then install the result.