It is my understanding that nobody is supposed to be sending any
without a nursery certificate.
I can tell you with certainty that some out-of-state plants (at least daylilies) can get interdicted here in CA if they don't have a certificate. (I've gotten a slap-on-the-hand letter from the USDA or whatever watchdog organization (and there are literally watchdogs (of the canine sort, not kidding) at the mail sorting centers sniffing out illicit plant shipments) more than a few times, because some nursery or other tried sending me a daylily without a certificate. ) Some such shipments (to me) were returned to sender (by the human watchdogs), some they let through.
Now whether or not irises will be let through, I don't know. If memory serves, the plants that were forwarded on to me even without a certificate (though there was that nasty letter), was because they were well cleaned bare root plants and the staff biologist inspecting the suspicious plant contraband decided that they were okay.
(Let me be quick to proclaim my innocence in those shipments; I had no clue that the "nursery" wasn't doing their job and did not have certification.
So my suggestion to you would be to clean the heck out of any rhizomes (foliage trimmed, no sign of disease, absolutely no dirt anywhere, maybe do a bleach dip), and include a cover letter in the package stating what the plants are (bare root iris rhizomes) and any treatment you did (bleach dip or whatever).