while the effects are mild on their own, i have had wonderful success vaping 10x Caapi in a "Crafty" vaporizer prior to vaping some freebase spice in a GVG. nothing at all like sublingual effects, yet the synergy was obvious.
i fill the bowl of the Crafty, set it at 400f and take anywhere between 3-5 hits a few minutes prior to using the GVG.
i would suspect the Volcano would be even more effective than the Crafty as the temp on the Crafty fluctuates pretty significantly. yet, it is simple, easy and works!