telijah, I have let CE4 clearos sit for weeks with juice in them and never had any issues. I would either just continue using them with the juice in them with great results, or clean them out, dry burn and change to a new juice. I do dry burn them after every couple/few tankfuls anyway. I've found they need that to stay good. The silica wicks do not seem to degrade when doing this, but leaving it too long will decrease their performance noticeably, leading to burnt hits, reduced flavor and vapor. Good thing is it's so easy to do.
I've just started to use menthol/mint and cinnamon flavored juices. They are pretty strong and so far have been the hardest flavors for me to clean out of a juice delivery system in prep for the next flavor. I have to take extra care with these and always now dry burn all the liquid out of the clearo when switching between them. OTOH, when switching between fruit flavors, drink flavors, or any other than the ones in question I've found it's easy - wash out the clearo, flick dry and put in the next flavor.