Mr. Snorggs's Thruster Wax is a product sold in the Terran Dominion that is applied to thruster boards.
During the Brood War, Dave of Rho Squadron kept a bottle of the wax on with to smell and remind him of his days boarding Miranar during its winter months. After Dave's death at the hand of a zergling, his squadmate Virgil Caine kept that bottle to remember Dave by.
References
Waugh, James. "A War On." (February 12, 2013). Blizzard Entertainment. A War On Accessed 2013-02-21.