Noisome Stone
Description
At first glance, a noisome stone appears to be nothing more than a smooth, fist-sized rock of dull grey or white hue. On closer inspection, faint oily streaks mark its surface, and a whiff of mildew or sulfur sometimes lingers in the air around it.
When activated, the stone releases an unbearable stench: a foul mixture of rotting meat, stagnant water, and acrid smoke. The odor is so powerful that most creatures gag, retch, or flee, and prolonged exposure can cause nausea and headaches.
Mechanics & Inner Workings
The noisome stone is an enchanted item. It remains dormant until its owner speaks the chosen command word. This command may be personalized upon creation, typically a single, petty word, with “begone,” “silence,” or “idiot” being prime examples.
Before activation, the current owner must mentally designate the next bearer of the stone.
Upon activation, the stone emits its aura over a large area, affecting everyone within range, even those incapable of smelling, as the enchantment assails the mind rather than the senses.
If the source of their malady is discovered and disposed of, the stone returns to the targeted individual's possession or appears in their dwelling or workplace within a week.
History
Legends differ on the stone’s creation. Some say it was forged by a deranged artificer who grew bitter at the world and sought to plague it with his misery. Others claim it was a prank gone awry. Whatever its true origin, all agree on one point: the maker’s intent was less grand sorcery and more spiteful nuisance.
Rumor holds that the first stone was tossed into a crowded guildhall during a heated negotiation, breaking the meeting apart and souring relations for years.
Significance
Prank or Punishment. The noisome stone is a favored tool among petty nobles, bitter apprentices, and rival guilds, who slip it into opponents’ chambers or marketplaces to ruin business.
Collectors. A few eccentric mages actively seek them out, believing the stones are the work of a legendary wayward wizard.
Dolvareth
Noisome Stone
Wondrous Item
Uncommon Requires Attunement
Activation (Bonus Action): Select a creature you can see. The stone becomes bound to that creature. Speak the command word to cause the stone to exude its noisome aura for 1d4 hours. After this duration ends, the stone re-activates automatically whenever anyone within earshot of the bound creature speaks the same command word.
Aura of Stench: Within a 50-foot radius, creatures must succeed on a DC 13 Wisdom saving throw or become poisoned until they leave the aura. While poisoned, they gag and retch, making speech and concentration difficult.
Persistence: The stone returns to its bound owner in 1d6 days after discarding it. The only way to be rid of it is to attune to the stone, then deliberately bind it to a new victim.
A small, smooth, indisinguishable rock, which under closer examination appears oil-treated and emanating a faint putrid smell.
Cost: 250 gp
Weight: 0.5 - 1 lbs
Uncommon
A small rock combined with a powerful enchantment

This has the potential to create so much delightful havoc XD I think my players will appreciate such a prank item as it messes with their heads :)
If you use it in your adventures, make sure to share how it went!
Will do! We are having a session tomorrow and I just might have the opportunity to do so :) Thanks for sharing!