Silver, Salt, Holy Water Test

As many supernatural creatures. demons and ghosts are vulnerable to silver, salt and/or Holy Water, these substances are used as a test by Hunters to help determine whether someone is human. It is a pretty fallible method - see below for the many times when it failed to detect monsters.

See also: Holy Water in the Face

Episodes

1.22 Devil's Trap

When Sam and Dean find John after he was abducted by demons, Sam splashes him with holy water to confirm that John is not possessed.

2.22 All Hell Breaks Loose: Part Two

When Ellen, presumed dead after the Roadhouse was burned down, appears at Bobby's hegets her to drink holy water to confirm that she is not possessed.

2.14 Born Under a Bad Sign

After Dean finds Sam holding Jo at knife point, Dean splashes Sam with holy water to confirm that he is possessed by a demon. Meg, in Sam's meatsuit, escapes and heads to Bobby's house, where Bobby discovers that Sam is possessed when he adds holy water to Sam's beer. Later, after Bobby secures the possessed Sam, Dean splashes Sam again to try to get the demon to talk.

4.01 Lazarus Rising

When Bobby finds a resurrected Dean on his doorstep, he assumes it is a supernatural being and tries to kill him. Dean tries to prove his identity by cutting himself with a silver knife, and they embrace. Bobby then checks whether Dean is possessed by dousing him in holy water.

4.19 Jump The Shark

When Sam and Dean meet Adam who claims to be John Winchester's son, Dean tests Adam with silver and holy water. He doesn't react to them, however he is not human, he is a ghoul.

5.02 Good God, Y'All

When Sam and Dean arrive in River Pass, Colorado, Ellen splashes Dean with holy water to check if he is a demon. Later, Jo splashes Sam, twice, because she thinks he is a demon.

5.04 The End

When Dean is captured by Future Dean in the year 2014, Future Dean tests Past Dean with Silver, Salt and Holy Water.

5.06 I Believe the Children Are Our Future

While they are not doused with holy water, Sam and Dean are covered with salt by Julia Wright, Jesse's biological mother, because she suspects they are demons.

5.15 Dead Men Don't Wear Plaid

Bobby tests his resurrected wife Karen with salt, silver, and holy water to try and work out what she is. She doesn't react to any, despite having been resurrected by Death.

6.01 Exile on Main St.

On seeing Sam, Dean assumes he is dead, but Sam assures him he is alive. Sam demonstrates he is human by cutting himself with a silver blade and drinking holy water and salt.

6.18 Frontierland

After Samuel Colt kills some demons, he is suspicious when Sam arrives, and so he splashes Sam with holy water.

6.19 Mommy Dearest

am and Dean find two orphaned boys named Joe and Ryan Silver. Dean says there are "a couple of dozen tests" to make sure they are human. It is unclear which ones Dean uses, but he fails to detect that Ryan Silver is a monster of the type Dean has dubbed Jefferson Starships.

7.08 Season Seven, Time for a Wedding!

Becky assures Dean that Sam tested her with silver, salt and holy water before he agreed to marry her.

7.17 The Born-Again Identity

When the hunter/taxidermist Mackey meets Emmanuel, he does the ritual on Emmanuel and tells Dean that he's the real deal.

8.01 We Need to Talk About Kevin

Dean returns from Purgatory and when he first meets Sam, Dean tests him with holy water, borax, and silver. Then, when Sam refuses to test Dean, Dean proves it is him by testing himself the same way. Later, Kevin squirts them with borax or holy water, it is not specified, however, Dean states that they are not Leviathans.

8.12 As Time Goes By

Sam and Dean test Henry Winchester with holy water and silver.

10.03 Soul Survivor

After turning Dean back from being a demon, Sam tests Dean with holy water.

10.06 Ask Jeeves

Dean and Sam test Olivia with what they think is a silver knife, but it is stainless steel, so she is able to hide that she is a shapeshifter.

10.07 Girls, Girls, Girls

In order to get the upper hand, Cole splashes Dean with holy water because he believes that Dean is a demon.

11.18 Hell's Angel

As Sam is performing an exorcism to expel Crowley from Castiel/Lucifer's vessel. Dean splashes holy water in Lucifer's face.

13.02 The Rising Son

This time it is Mary Winchester on the receiving end when a hunter splashes her with holy water to test whether she is a demon while she is trapped in Apocalypse World.

13.18 Bring 'em Back Alive

When Lucifer attempts to help two priests in the midst of an exorcism, he reveals to them he is the Devil and running Heaven, causing the priests to throw holy water in Lucifer's face.