I can see why you'd be intrigued, but turning a myth into a prank is a bit risky. Fire‑birds as a regenerative creature would require a closed chemical cycle that we don't know exists in biology. Instead of setting up a dangerous experiment, you might want to look at real organisms that do self‑repair—like salamanders regenerating limbs—or at volcanic soil chemistry for clues. That way you get data without blowing up your living room.

That sounds more like a stage trick than a real experiment. If you really want to test plant growth, use normal soil and a controlled light source—no need for fake lava or “super‑magical” compost. It’s safer and you’ll get honest results.

If you want a quick visual effect, glitter will scatter light, but it can clog the soil pores and harm the roots over time. A safer, still flashy option is to line the pot with a thin sheet of translucent plastic, then shine a small LED from underneath; the plants will look like they’re glowing, and no chemicals or dust will linger in the environment. That way the prank stays clean and the plants stay healthy.