In reality more atties are killed by cleaning than anything else.
I simply flood my atty (two or three extra drops), and blow any crud build up out the bottom of the atty. If I think the atty needs it I will let it soak in alcohol for a while and then blow it out. I might do that once a month or so. There is no need to let an atty sit and dry out. You will find that alcohol a common ingredient in e-liquid anyway so any residual will simply be absorbed by your juice. Also never store an atty dry, there is a reason that they come with a primer in them. So always put a couple of drops of juice in them if you plan on putting them away for a while.
I'm using atties that are well over a year old, both for direct dripping, and on my REO.
Regular rubbing alcohol?