I vaguely recall (it happens in your mid-70s) having read or perhaps heard that there is an extension that can be run on a drawing to remove all guidelines one has inserted to clean things up.
Is there such a tool or am I having another senior power outage? I did a search in Extension Warehouse but didn’t see anything that I thought fit the bill.
Menu: Edit -> Delete Guides will delete all guides from the current context downward. So if you select Delete Guides at the Model level, all guides are deleted.
As Jim says, Edit>Delete Guides will do the trick. You may be confusing the idea of a plugin with me telling you I set a keyboard shortcut for Edit>Delete guides. I know I mentioned it in one of our sessions.