It takes a little bit for water to dry up in an atomizer. If you try and use it to quickly then the water will cause the atomizer to heat up to quickly. Which can lead to issues to where the coil gets to hot and pops all of a sudden.
Also, it will won't perform as well neither. Which was the biggest problem for me since the flavor, vapor, and TH was really off. You can use something like a hairdryer but, I found that has little effect in drying it. Lastly, you want to make sure if there is any iso that's left in there then it has time to evaporate. Really don't want to vape that stuff.
With cartos, it takes longer then you think. Especially when you live in an area like Western Washington that isn't to warm most of the time. So, it actually takes about a week to dry. If it's a EMDCC then it will take longer then that. Ultimately, that is only one reason why I stopped trying to clean cartos in general.