Well, it's a good idea to do this in a cool environment, I see you have selected your fridge to do the task.
I hope it's an old fridge that doesn't have actual food in it, because that naptha has got to go somewhere. It will evaporate into your food!
If you attempt to do this on a hot day, it's quite possible your crystals will melt. So make sure to do it in the coolest/driest area you can. This works better in winter. And yes, once it's poured off and has been drained upside down for a while (keep an eye on it so it doesn't melt) you can just leave it for a while so it completely dries.
Also when you scrape it out, that will help to release any trapped aromatic hydrocarbons in the crystals if there were any in there to begin with.