The hollowing through the rhizome looks like borer activity. The yellow dots could be frass from the borer as it ate down the leaf and into the rhizome. Since you dug them up and gave them bleach bath it is pretty safe to say there are no borers still alive in these iris. Cut off any soft spots still on the rhizomes and let them dry a couple of days. You can then replant the rhizomes that have fans. In the lower of your two photographs I would discard the rhizome at the top that has no leaves because the borer tunneled all the way through and it would be susceptible to rot. The iris on the bottom left - I would cut off the right side rhizome that has no fan, and plant the left side rhizome.
