And so when you go to cement your casing in place, you, what?, cement your brand new indestructible quaise 'drill bit' in the hole? Sorry, I think not. Neat id

And so when you go to cement your casing in place, you, what?, cement your brand new indestructible quaise 'drill bit' in the hole? Sorry, I think not. Neat idea, but there's big holes in that in practice.