I have read that deleting objectsimported in Home is quite easy. "B" button, Click "Remove Upload", close Oculus, go to _Import directory, manually delete the objects, restart Oculus, go to Home, and voilà, object(s) no longer visible. There is one problem with that. It does not work. My son created huge objects in Medium, imported them in my Home. I removed the objects in Home, did the "Remove Upload" trick, waited (in fact a few hours, not just a few seconds), deleted the objects in the _Import folder, emptied then deleted the very Home it had been put in, searched all my HD for the file ("zach") (deep search, with research extended to hidden files and the content also), even searched the Registry. To no avail. Restarted Oculus software, restarted Windows. The object is still there, in my inventory, each and every time I return in Oculus. Where is the damn file on the disk? Or the setting? Should I uninstall all and everything? Why is it so... persistent?
I have the same problem. I downloaded a 3D model of Motoko Kusanagi from Sketchfab and it was huge!!
In short I ended up with over 20 models in different sizes, used the same methods you described and all the models are still present. It's been nearly two weeks and I still haven't found the solution to this problem.
Strange... all of a sudden, the deleted objects are correctly disappearing from my Home Inventory. I have had that problem for the last month, and today, out of nowhere, it does work as it should... I am perplex, but happy! Maybe my Home had been shared by friends, and was sitting on the Cloud or on their computer, and when they logged in, the cache updated and let me erase properly. A bit like if I try to erase from the inventory an object that is already placed in one of my Home. First "unshare" your Home, make sure nobody is visiting it. Then remove the object (in Home, select object, and press « B » ), then erase from the inventory (Inventory opened, point at the small image of the object, press « B », select "Remove Upload"), then erase the file from _Import directory (in Windows, not in VR), then reopen Oculus and log in Home. Repeat all the above and be patient if it does not seem to work. It definitly needs to be easier...