Negative on the corn starch mixture. Didn’t think it would work but had to try it. We have various natural clays that would thicken in the lab but I’m not sure about putting those on my hands. Natural doesn’t always mean safe.
I guess the easiest is putting some 60% minimum IPA (Isopropanol) in a spray bottle and spritzing your hands or some other alcohol that’s at least 120 proof (save the vodka and tequila for drinking). I’m sticking with 60% minimum concentration by weight as my own internal guidelines for what I will be willing to use. Using a measuring cup is a volume concentration and I’m not sure what % alcohol you’ll end up with. Would need to know specific gravity of each material. (See below..I’m not good at leaving such things unanswered)
While I was typing I decided to pull a couple of SDS for hand sanitizer off the web. I suspect that they are 60-70% alcohol, 1% aloe (just enough to claim) and the rest are viscosity agents. First one I pulled is Purell gel and it says it’s hazardous components are Ethanol 50-70% and Isopropyl 1-5% so by that it does dip lower than 60%.
While I’m playing on the web. Specific gravity of aloe very gel is 1.027 roughly. IPA is roughly 0.7885. 1 US cup is 236.6 ml. Doing some math at 1/3 cup and 2/3 cup gets you:
.33 cup x 236.6 ml/cup x 1.027 grams/ml = 158.26 grams of Aloe
0.66 cup x 236.6 ml/cup x 0.7885 grams/ml = 123.1 grams of IPA
That ends up 43.75% IPA if you were starting with 100% material. 124.1/(158.26+123.1)x100=
pretty sure I did that right but I haven’t had enough caffeine yet so I’ll check it after the brain is functioning fully.
ETA: I pulled 1 SDS for aloe gel to run the numbers with, not all aloe gels have same specific gravity based on the next SDS I pulled. I would use a kitchen scale if I was making it at home.
ETAA: pulled SDS for another hand sanitizer it says they use 50-100% of 70% v/v which means volume per volume and glycerine plus other ingredients. I have glycerine and it does thicken things but all the math variants are driving me a bit batty.
Screw it, wash your hands with soap and water for 20 seconds.