You can do things while in the bank. Do some fletching, alching, disassembling, or whatever for an hour while in a bank to get the achievement.Glad to be of service (Powered by GPP™ - Share and Enjoy!)
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You can do pretty much anything while bankstanding, just don't leave the healing area. Fletching/alchemy/herblore/chatting is stuff you can do to pass the hour. https://runescape.wiki/w/Questioning_Your_SanityThe Winner of September 2019's MUPAQ™ Award is
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