Not only that, but disposing of bodies in those ways is rare on the whole.
Look at this wood chipper idea for instance. That requires BM to get a hold of that machinery when he was still struggling to figure out how he was going to handle his alibi.
Then he has to use a machine that leaves a tremendous amount of evidence in its wake (blood, bone, hair), and he obviously would have had to get rid of that equipment too.
Hell, that’s as difficult as getting rid of a body.
His major issue here was a lack of time (last minute alibi). Add in something “creative,” and it just doesn’t seem to work.
I think he went about this the easiest and most effective way that he possibly could.
He buried her somewhere remote.