Dressing to Go, Salad Dressing Containers 3pk D2G-3PK-AMZ

Does anyone have the height measurement? I want to make sure they will fit in my salad container before ordering!

How do you best clean the inside of these? The shape of the silicone makes it seem like it would be a challenge.

2 pk or single? I see 1 in the pic & complaints about being sent only 1, but title clearly says (2 pk)?

Do these discolor or stain when using ketchup or balsamic dressing, for example?