I have a lot of never again used stuff in the local memory of my K1. But it is almost impossible to delete these models. Sometimes, but very rarely, I can see a blue V sign in the upper left corner, then I can delete that model. But I have no idea how to reach that state. Otherwise, the delete field comes up, but does nothing.
I hope my somewhat limited knowledge of the English language is good enough to explain my problem.
Can’t you select all of the files in Fluidd and delete them? I find this to be the simplest way. Only works if you aren’t currently printing, you can delete everything except what you are printing.