I actually thought of a successful way to slip this to your target (let's assume we want to assassinate the king, or whatever).
1. Make this spell into a Potion.
2. Cast Prestidigitation, and use it to alter the flavor and color into that of [tasty beverage] of your choice.
3. Put it in an appropriate container; ensorcel the contents to remove their aura of magic (Nystul's Magical Aura makes a nice stopgap measure, though at higher levels, something more potent is probably more appropriate.)
4. Hand it to the Rogue, and have them trade off the drink at some point.
5. ???
6. Profit!
As a DM, I would be totally fine with it if one of my players thought this up; it shows initiative and creative thinking on the part of the player.
Oh, and as an added bonus... Delay Spell and Fell Animate are fun metamagic to apply to this spell.
Finally, something that probably wasn't an intended use... a final measure for a spell, much like a cyanide capsule; the spy triggers the spell, thus killing themselves before questioning can begin (of course, they are going to add some other spell in there to prevent Speak with Dead.)
