Since no experts have replied, I will. VG is sometimes thinned with distilled water, PG or PGA. 4 parts VG to 1 part distilled water maximum. I've done it myself. One vendor ( I forget which one ) gives you an option for straight VG or thinned VG. Thinned VG is probably less likely to gunk up your attys. Straight water? Maybe for cleaning if you let it dry really good.