It's not realistic. It's one of the stages we all go through along with things like "doing it so I can be an organ donor" and "disappearing entirely with no trace". None of these things including "accidental" are IMPOSSIBLE. They are just HIGHLY unlikely to work even with intense planning. With the sort of half-assed planning most of us are actually capable of in this state they won't work at all and are obviously staged or "weird" to any rational person. Like the "falling off a cliff" idea sounds sensible...but if you never hike and people know you are depressed (and people know) nobody is going to buy you suddenly became an outdoorsman and had an accident...especially not an insurance investigator if your reason is to hack the life insurance clause for example.
It's a normal desire...but one my advice is to let go of and focus, IF you must CTB, on a method that is safe, reliable and peaceful first and foremost. Adding complications and showmanship adds chances for failure.