Harder requirement to get Lava Chicken Disc

Right now the only requirement to get the new disc is killing a baby zombie riding a chicken.
This is too easy.
Suggestion:
You should be required to burn the chicken with lava after killing the baby zombie.

*A fire aspect sword would not work
*Up to mojang, flint and steel is enought for the requirements.
If it's left in the current state that it is, there will be an overflow of useless disc once you get yours.

If users have difficulty getting the disc because the chicken die IN the lava, a splash potion of fire resistance should give you plenty of time to burn it and wait for the effect to run out.