This looks super fun! What's the viability of doing this at an artisanal scale in the kitchen? E.g carving a mold out of something, melting plastic in the hob,

This looks super fun! What's the viability of doing this at an artisanal scale in the kitchen? E.g carving a mold out of something, melting plastic in the hob, and pouring it into the mold? I remember as a kid my dad once got some sort of plastic that you made by mixing two liquids (they were very liquid, so not epoxy), and I made molds of things out of putty (or clay?) and then "copied" them with the plastic. Any idea of what this room-temperature binary-plastic could be?