Allow sinks to be catalysts for alchemizing things. (Or possibly add a “cauldron” as a new piece of dungeon furniture, but that’s iffier.)

• You can dip potions into sinks to pour them down the drain, experiencing the vapor effects in a safe way. (Pouring polymorph down the sink of course polymorphs the sink.) This requires vapor effects to be implemented for many of the potions that don’t currently have any.
• If you don’t pour the potion down the drain, you instead mix it with the fluid from the tap, which is usually water but can already be a random potion.
• Possibly, doing alchemy in/on a sink is more efficient. There are many possible forms this could take, such as:
  • Potions not diluting when you mix them.
  • Reduced or zero chance of an alchemic blast.
  • You can get results from mixing potions that you can’t otherwise. (Flavor for this is weak. Is the character heating them somehow with the hot water?)