Never knew why people did lobs. I've got 99 Summoning 3 times... 2 of those times 97 - 99 was in one day, or just over, including collecting the charms at waterfiends / TDs (for effigies). They may be boring and require more attention, but it's still very fast. if you need mage xp and charms, there is no better place true but in general slayer is more efficient, as you can summon and slay with no loss to slayer xp, while there are better ways to do magic than rock lobs. and if you already have 99 summoning you can actually get rock lob types of charms/hr at chaos tunnel waterfiends for a lot cheaper. but I suppose that's irrelevant for most people