Rubbing alcohol is usually toxic isopropyl alcohol, but it is denatured and undrinkable even if it is ethanol-based, due to the bittering agents added. As a high-functioning alcoholic, Archer would of course know this.
While it is true that rubbing alcohol is toxic to humans, both Malory and Archer have imbibed large quantities of both rubbing alcohol and isopropyl alcohol (e.g., see Sea Tunt: Part 1 (2013) and Sea Tunt: Part 2 (2013)).