Im doing my slayer task of dust devils. As Im merrily slaying away, I notice that as I kill them, the bones keep dropping on the ground. Why isnt the bonecrusher burying them for me? They are jsut regular bones, but I still want my xp.

The bonecrusher doesn't work with x2 drops. I assume you are killing them in the chaos tunnels. I had the same problem with the Fire giants as well.

 

The urns are bugged as well - it collects only 1 ash and the 2nd one doesn't drop nor it gets collected.

So neither of the bones get crushed? because I dont think im getting any prayer xp at all

 

And yea, im in the tunnels

Nope, the bones are left untouched.

Well thats just all around stupid. Also, are charms double too? I havent really been paying attention

EVERYTHING is double, meaning - yeah even the charms. I got quite the nice pile at Nechs.