1. CREATE A HUGE KEY.
2. DEL it
3. CREATE A HUGE KEY.
4. DEL it
In steps 2 and 4 we know that we always reclaim the memory if we use DEL, so step 3 is never going to use more memory than it was used in step 1. Instead change this with UNLINK. Potentially UNLINK is still freeing memory as we now create back the key again, technically using more memory than the previous peak memory.
This in practice is hard to trigger since asynchronous deleting is faster than the time it gets you to build new sizable data. But I still thought this was an important difference that deserved a different command name.
Otherwise people will assume something a lot worse is going on given how you phrased it.
*but you could always add a footnote to avoid conspiracy theories about the CIA's efforts to infiltrate your memory reclaiming strategy.