Can't offer any suggestions because I never got it to work in a clearo. My experience with this was a bit different. I mixed up a batch of DV KolaKick and vanilla (don't remember if it was DV Very Vanilla or PR Vanilla or a combination of the two) at about 50/50 cola/vanilla (all VG mix). Loaded up an XL clearo. Set it down to do something else. Came back to it a few minutes later and it was cracked. Badly cracked and leaking all over the place.
Figured it must have been a bit cracked before I put the juice in it and I just didn't notice it, and maybe I'd mishandled it and made it worse when I filled it. Grabbed another clearo, inspected it to be sure it didn't have any cracks, and filled it up. Set it down. About two minutes later I looked over and.... well, it wasn't cracked this time. It was completely broken.... I mean in about 10 pieces.
Just the guts laying there surrounded by broken plastic and cola juice.
I decided it must be something in the juice (caffeine maybe?) causing the problem. I've only used Kola Kick in Tanks or dual-coil cartos (the metal body kind) since then.
Anybody else had anything like this happen to them?