Not replying to the request for 100% VG, but my favorite menthol is:
A very suitable DIY blend can be made with menthol, peppermint, wintergreen, and sweetener. Look for "MMM" in the DIY recipes.
I just ordered the menthol sampler pack from Halo. Their site doesn't say whether it's more pg or vg. I can't take too much vg. Does anyone know which one is predominant in their juice?