Not long. If I'm co-washing, it's just putting in the conditioner, rinsing it and then applying a heavier one. I let it sit while I shower, then rinse again.
I don't "do" my hair. If I wash n go, all I do is add in some leave ins & let it airdry. If I'm wearing a bun, I pull it into a ponytail while it's wet and then create the bun. Total time is about 30 minutes.
Once a week, I try to do the works: pre shampoo treatment, shampoo, deep conditioner and wash n go. Now that's longer.