I'm not sure where I've been for the last 10 years that these "revision clocks" have existed, but I'm loving the opportunity to focus students' attention on specific regions & themes and create a placemat that they can then study from. Keeping the clock consistent for regions & themes can help show some changes & continuities over time. This resource suggests using one of the blocks as a break, which can help break this type of resource into smaller chunks.
Our class periods are 59 minutes in length, so this is something that we can manage in one hour -- when class begins at 10:40, they have 5 minutes to add into into that section before moving on in 5 minutes, then a new topic / theme at 10:45, etc. I'd circulate as they jot their notes down, clarifying, correcting, suggesting, etc. as time proceeds. Working at table groups, students could check in with each other.