User Subscriber Count Incorrect

Since I no longer require registration to comment, I was going through and cleaned out all the users marked as Subscriber. Now when I go to the Admin/users page, no subscribers come up in the list, but the count at the top says “23”.
A quick look at the wp_usermeta table shows some entries that are obviously spammers in meta_value, and along with them there are some “bb_capabilities” entries which I am assuming are from when it used to be linked to a BBPress site.
Not being an sql genius, I don’t know how to clean them out (or if I should worry about it).