The first question, that may arise, is why to bother cannoning these dangerous creatures deep in the Waterbirth dungeon? The answer is - it is one of the fastest blue charms getting method. The also drop some nice regular loot of pure essence and runes, as well as body pieces for rare skeletal armor.
What to take?
Take the maximum prayer gear you can get, a ranged weapon (crossbow prefered), a cannon of course, about 10-14 prayer (4) potions, holy wretch (Iforgot that during my run, but you shouldn't), a ranged potion or two if you want, about 2-2,5k cannon balls, a one click teleport, a shark (you might get damaged while running into the final destination).
Where to get them?
In the Wallasalki dungeon, of course. In the first level there in non-multicombat area, so they retreat and it is hard (but not impossible) to kill them efficiently. The place to kill them is further into the dungeon. After getting past the first doors with a help of a friend, you go to the very end of the level and use the rune thrownaxe special on the baricades, then go down (make sure you first activate pro-magic prayer first). There you will see 3 wallasalkis there, but its still not the place to cannon them. Go further, you will enter the room with daganoths (pro-range here and run, meelee daganoths can still hit you, so better hurry), then further into the room with giant rock crabs (pro-meele here),then further into another room with daganoths (pro-ranged again), and then further into the room with wallasalkis (activate pro-magic and now don't turn it until you leave by teleporting out
The tactic
Setup the cannon here:

Then just reaload and fire it, youself standing in one place and firing the bolts. Run only of you need to take the drop. I myself went with meelee gear, that proved to be a big mistake, as I had to run more, offen causing wallasalkis to folow and pile on each other. And piled Wallasalkis are really bad, as you cannon can't efficiently kill them. If this happens, run to near room with rock crabs, and return. By that time, Wallasalkis will be spread.[/b]
The cost
For about 1h 20 min, it took me 2300 cannon balls and 11 prayer(4) potions. Thats about 469k cost.
The drops
In that time I got 77 death, 30 blood, 32 chaos runes, 135 pure essence, 1 rannar, what costs about 60k. The problem was that I took too many prayer potions, so at first didn't have place where to store the drops, so don't make that mistake and you will get more loot. Also, I took a nature and a cosmic tallies, thinking that they are usefull - they are not.
From the rare side, I took back 3 skul piece, 2 fibula piece, 1 ribcage and 1 skeletal gloves, that cost about 133k.
So in total it seems that I lost quite a lot of money, with loss being about 336k. But the part where I was shocked was when I looked into the GE prices and saw that skeletal gloves are worth 40k and skeletal boots 10k. I was unaware about that, so there in the dungeon I left no less than 3 skeletal gloves and 1 skeletal boots lying on the ground, and probably more. So that would be at least 130k more from drops. So in total for 1h 20 min of cannoning wallasalkis I would have lost about 206k. Still quite a lot, but this is for the a bunch of charms and some nice ranged exp (haven't tracked it, but pretty sure its no less than 30k/hour, maybe about 35k/hour). Also, if you kill meelee daganoths for crimson charms, you will also get a bunch of daganoth hides. Use them and the body pieces to make full skeletal armor, it seems it sells for little more than the part.
Charms
In 1h 20min cannoning session, I got 38 gold, 14 green, 16 crimson, 24 blue charms. Quite a lot, I would say.
So thats all. The results, unfortunatly, are only from 1 run, so its's nowhere near the normal guide, just wanted to share some information with you, guys.

