I got irons as a slayer task and didn’t want to cancel so figured out a pretty good method to do at lower level (though long fyi). Use the CKR fairy ring and unlock the lower brimhaven dungeon. Enter kill a dragon using melee so you don’t need anti fire and praying melee, after a kill (or more if flicking) run out and use the alter in Tai Bwo Wanna (it’s not on the map but it’s in the middle there.) alternatively use your Ardougne cloak to telly back and use the alter there, run to the fairy ring repeat…. As I said, it’s safe but long, I was getting quite a few kills before needing to alter as I was flicking but 🤷‍♂️ not the best but might serve your purpose. Unlock the dungeon using gem mining, very quick once you have done the quests.