Spores can be an issue. One trick to get rid of spores is to allow them to germinate: a day in water at room temperature would do just that; it's a trick a lot of fungi enthusiasts use for their substrates. Hot water should kill a lot of plant infecting things.
Like hot tap water hot, not boiling. 10-15 minutes should do the trick. Longer is better, but 90 minutes should be more than enough.
(The fungus people do a full autoclave sterilization, under pressure, that'll destroy your pots)
Do the bleach afterwards (and do add dishwashing liquid to decrease water surface tension and increase penetration). Then rinse with water three times and leave them in tap water for a day.
Weirdly enough, a solution with insane amounts of sugar or salt will have almost the same effect as bleach.