Crimson Charms Required
(92-95) = 5085 x Wolpertinger.
(95-96) = 2187 x Iron Titan
(96-99) = 7931 x Pack Yak
(92-99) = 15203 Crimson Charms
I should read up on this.
Waterfiends
According to wikia, can break even / profit at waterfiends, via noted water orbs, noted snape grass, water talismans, ranarrs, lantadymes, clue scrolls, water battlestaves. Especially with a ring of wealth, I think I'll make money from it, perhaps even enough to pay for summoning.
If I use a bunyip, I can use the swallow whole scroll to eat the raw fish dropped, but won't have the healing power of a unicorn stallion. Due to maxed combat though, I think I should be fairly okay, so probably end up using bunyip.
There's a 76% chance of a crimson charm drop, therefore need to kill just over 20k waterfiends.
Outfit
Helm of neitiznot, Karil's leathertop, Karil's leatherskirt, Barrows gloves, Dragon boots, Glory, Fire cape, Saradomin godsword, Ring of wealth, Bunyip.
Inventory
(Use soul split!) 5-6 prayer potions, 2x extreme att, str, alching runes.
Effigies
Level 115, approx 1/1k effigy drop rate. This means 20 effigies.
Summary / Notes
Overall, this sounds like it might be alright. Some profit, lots of charms, the thrill of unknown drops, it'll be just like slayer! Equipment is also really cheap, only a few mil, meaning I can get the charms fairly easily, even if I can nowhere near afford 99 summoning.
Also, as I'm 99 def, mage, range, I *may* be able to just tank it, and not need to pray, just worry about picking up drops. I'll pray to start with, then see how it goes.