Specifically, the menthol lovers sampler from V4Life. I vaped them all till near empty, found I liked Cool the best and got a bottle of it. I figured I could add the juice to the used cartos and combine what was left of the different flavors with the Cool. Well, it hasnt quite worked like I hoped it would. Only 2 of the initial menthol flavors are combining okay, the Smilin menthol and the Nuport. But, fwiw, none of my experiments beats the taste and performance of the juice in a brand-new, blank carto.