yup... wax is a pretty interesting material. i think i'm the regular he's referring to =)
one idea i had when i was in an arts/crafts store recently was a print head that could take crayons as feedstock. they are widely available in a variety of colors, and are a pretty standard size. they are also fairly cheap.
this is a potentially very excellent material. theres also alot of room for innovation. stick around and see what happens!