Why do certain smells stick to your hands, especially when cooking or during scientific experiments?

Answer 1

Exactly same as to why perfumes linger for a time.
Our skin is a bit porous .
Organic compounds, especially aromatic ones during cooking or experiments, stick to your hands( the pores)...someimes even after repeated washings .
These particles continue to give smell.... thus the smell does not come off the hand easily

Answer 2

Your skin absorbs moisture. And almost every time doing cooking or scientific experiments you are using liquids.

Answer 3

could be moisture.. more likely to be the skin absorbing flavours and smells transported in oils. The oilks are more likely to be absorbed, and less easy to remove.