If you have 43+ prayer and 70+ mage with ancients then go to rock lobsters, 130-150 crimsons an hour. There's plenty of guides on how to get there and lure them on youtube.
You'd mostly need 43+ Pray if you want any good charms, the best places for pures would be bursting rock lobs or killing waterfiends (Pray untill they're unagressive) then you could safe spot them.