New to the chicken scene, and my 3 pullets have so far successfully ignored my attempt of making them a dust bath 
They seemed to have picked the corner of a dried up flower bed. I've seen them attempt to bathe there. But it's got me thinking, what are the best ingredients to put down on dust bath?
Dry earth, sand and a DE?

They seemed to have picked the corner of a dried up flower bed. I've seen them attempt to bathe there. But it's got me thinking, what are the best ingredients to put down on dust bath?
Dry earth, sand and a DE?