"Sleep Clause: Only one Pokemon may be put to sleep on the opposing team at a time, if not induced by a move such as Rest."
I suggest to make it 2 pokemon at a time or adding any sign that the opposing team has already a sleep pokemon at a time.
I suggest this because i saw many pvp player using blissey and starmie with natural cure ability.
Reason i post this because i play pvp then i accidentally sleep two poke the blissey and milotic.
Everyone knows that the pvp pokemon like blissey has a natural cure ability so when they switch out they will cure the sleep illness.