Ihub has duplicate policy for repeat posts back to back or the same day...It could clean up some boards if individuals that are lazy just copy the same post and duplicate them every 3-4 days and continue to post them for 6 months.
I like ignore idea by home brew. After a week or two I unignore them, read their posts, and usually just put them back on ignore for good.
All of my posts are strictly opinions and should not be considered to be facts, or investment advise.