In my test, which went for exactly one hour, I was able to pick up and bury 377 Big Bones. This gave me 5655 experience.
If you were to be perfect with the route, keep walking without stopping to pickup bones, and bury the bones with the minimal delays you could easily reach 425 in an hour.
This is just for anyone to reference if they want 43 prayer before this weekend. 10 hours is not bad but I wouldnt bother if you are just starting, more useful if you are at 33+.
Aggression from the skeletons seems to take more than ten minutes. There are spots by the two big bones closest to each other where you can trap 3 skeletons and then only have to deal with 1 at a time while still getting big bones. They have some interesting drops and there is a iron scimitar nearby.
Based off other posts, people dont seem to have shared that if you stick to between the three bones on the western edge you will not regain aggression from the skeletons. Watch out for the one who has a huge roaming area, almost always will have to kill him. Reminds me of the Terminator.