I've really been satisfying my slip trailing fetish lately, which means filling up the slip bottle more often. Since a batch is way more than my slip-trailing pen can handle, I've just been storing the leftover in the blender, which works okay until I need the blender for something else. (No, not margueritas. I have another blender for that.) Also, the spout of the blender is so wide and the neck of the slip bottle so narrow that it's a big sloppy mess every time.
I just happened to have used up the last of a bottle of conditioner this morning, so when it came time to mix up a new batch of slip (more about that here)I dug the old conditioner bottle out of the wastebasket and rinsed it thoroughly and - voilà - a slip storage container that makes it easy to fill up those little bottles. The cap of the conditioner bottle comes off, revealing an opening that is much larger, although it's still a bit of a mess; but, importantly, I only have to fill the conditioner bottle once per batch. After that i can just easily squeeze into the slip trailer. It looks a lot messier in the photo than it actually is, because I needed one hand for the camera, but trust me: it's sooo much easier. And the blender is freed up.