I don't use removable media, so I don't know exactly how it works. Maybe it's "smart" enough to distinguish removable from fixed drives. Why don't you tell us?
If it does distinguish removable drives and you use removable media, then obviously you'll want to use this filter in the normal manner. Another option is to use the loan feature to tag movies, and then use the loan filter to include/exclude them. This has the additional benefit of colouring the entries in the list so they are distinguished from other movies, even if not hidden. So, for example, you might "loan" movies to "Deleted," then set "Not loaned" to hide them. I do this for movies I've seen "by accident" and for movies I never want to see but are included in my database because they are part of a series.