Which "wool" for bass trap?

[cooker]

I'm sort of confused about selecting material while reading these threads. I'm not sure if I can find all of the mentioned ones here but pretty sure glass and rock wool should be easy to find.

Fiber glass seems to be mentioned a lot and also I wonder if lamb's wool (if I can find it) should work well?

My current room is pretty small (I change places every 1-2 years). I'm going to start with the corners and maybe behind my nearfields (though not sure if it will help anything). Any advice is welcome.