There are many differerent methods used for breaking seed dormancy. But basically they fall into 7 groups.

Fire is a form of seed scarification  or it could e a heat treatment. while there are seeds of various species that respond to either or both of these tretments, iris are not included in this group.

Smoke?, never heard of this one. But basically could be an amature method of  providing heat shock, which works with some species.But not iris.

For chemical tratment, there are three forms of this

1)  removal of seed  inhibition chemical. Water does this just fine
2) Scarification. That is damage to seed coats. I  have seen many exotic  means of this. Some work. Soaking in concentrated sulphuric acid for periods of 5-35 minutes  can remove seed coat.  But so can sandpapering seeds, tumbling in sharp gravel,  or cutting seed coat. Iris don''t need this, except for aril seeds.
3) Providing germination plant chemicals needed. Such as a  Giberellin acid.  But plant will provide theese chemicals once proper treatments, such as removal of inhibitor chemicals and proper chilling

I haven't seen any of these methods used or recomended for iris seeds recently. If  you have, could you let us know where you have gotten such recomendations for iris seeds, and what they are?

Chuck Chapman