Touch-Taste Cell Permeability?

Whoo. Okay- chemistry class flashbacks for me.

I know I've seen a chemistry experiment that involves someone touching
a powdered' chemical with their finger- and immediately being able to
taste it because it penetrates the skin and bloodstream.

Sadly, I cannot remember what this is CALLED, and blind-googling has
not yielded an answer. Can someone help me? What chamical am I
thinking of? What's the effect called? Is this related to the way
dimethylsulfone works? Do many chemicals have this property?

....help?

Responses appreciated, thanks for taking the time to read.

-Derik

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