Bookmarking toots: Thanks to the brilliant tips by obscurosaur, I have tried & tested two methods:
1. Reply to the toot with a unique hashtag. Remove the id of the tooter. If you remove id, the tooter can see the reply if they check, but will not get notifications.
2.Reply to the toot & DM to yourself. Remove the id of the tooter. The tooter will not get your reply.