It dries to a durable hardness depending on the temperature, my shop is pretty cool (55F) and they were nice and dry in a few days, probably works faster in a warm shop.
I think the Cosmoline has gotten an undeserved bad rap for collecting dust, wiping off, etc. The stuff is plenty durable for a car that is treated on the pampered side and driven mostly in nicer weather. While you can grab it with your bare hand and feel a waxy tackiness, it's pretty darn tough, it doesn't rub or wipe off easily at all. Regular dust and dirt washes off with a water dampened rag leaving the Cosmoline behind looking unscathed.
