If all you need is to cover your tracks on a video that your roommate will never click on, you're totally safe! But one problem persists: if she clicks on that same video someday, "continue watching" will show up instead of the standard "Episode 1 Watch Now." Even if you delete everything, you'll need to go into each episode and rewind it to the beginning, or risk people knowing that you watched Bosch. A gray bar will still appear under the video, but at least the green bar will be gone. So if someone is watching on a Fire Stick, they probably won't notice.
Now, we understand how mortifying it'd be if you really were caught watching Bosch, so we dug deeper -- and we found one of the most futile Amazon help threads in existence. Turns out no one knows how to do a full reset, although if you have a Samsung smart TV, you can sometimes get this to work just by deleting items from the list. If anyone figures out a more reliable technique, please go to this desperate, desperate thread and help these guys out (and us, really).