Add this to your custom map folder/campaign folder's objects.cfg (adjust the id numbers as needed so they are the numbers directly after your highest)

[object146]
Name = POTION_RED
Genre = DECORATION
AnimationID = POTION_RED
AnimationSpeed = 256
Size_XY = 0
Size_YZ = 0
MaximumSize = 300
DestroyOnLava = 0
DestroyOnLiquid = 1
Health = 0
FallAcceleration = 0
LightUnaffected = 0
LightIntensity = 0
LightRadius = 0
LightIsDynamic = 0
Properties = CHOWNED_ON_ROOM_CLAIM DESTROYED_ON_ROOM_PLACE

[object147]
Name = POTION_BROWN
Genre = DECORATION
AnimationID = POTION_BROWN
AnimationSpeed = 256
Size_XY = 0
Size_YZ = 0
MaximumSize = 300
DestroyOnLava = 0
DestroyOnLiquid = 1
Health = 0
FallAcceleration = 0
LightUnaffected = 0
LightIntensity = 0
LightRadius = 0
LightIsDynamic = 0
Properties = CHOWNED_ON_ROOM_CLAIM DESTROYED_ON_ROOM_PLACE

[object148]
Name = POTION_WHITE
Genre = DECORATION
AnimationID = POTION_WHITE
AnimationSpeed = 256
Size_XY = 0
Size_YZ = 0
MaximumSize = 300
DestroyOnLava = 0
DestroyOnLiquid = 1
Health = 0
FallAcceleration = 0
LightUnaffected = 0
LightIntensity = 0
LightRadius = 0
LightIsDynamic = 0
Properties = CHOWNED_ON_ROOM_CLAIM DESTROYED_ON_ROOM_PLACE

[object149]
Name = POTION_YELLOW
Genre = DECORATION
AnimationID = POTION_YELLOW
AnimationSpeed = 256
Size_XY = 0
Size_YZ = 0
MaximumSize = 300
DestroyOnLava = 0
DestroyOnLiquid = 1
Health = 0
FallAcceleration = 0
LightUnaffected = 0
LightIntensity = 0
LightRadius = 0
LightIsDynamic = 0
Properties = CHOWNED_ON_ROOM_CLAIM DESTROYED_ON_ROOM_PLACE