There seem to be only two places that the name Iromenis is actually mentioned, and this is only because of Georg Dehn with his German translation of the Book of Sacred Magic of Abramelin the Mage. On Joseph H. Paterson’s site Esoteric Archives, or otherwise known as Twilit Grotto, the txt of the book is mentioned with a note by Dehn, and it is that note where the name Iromenis appears.

The text itself reads:

The following be those of ASTAROT, viz.:
Aman. Camal. Toxai. Kataron. Rax. Gonogin. Schelagon. Ginar. Isiamon. Bahal. Darek. Ischigas. Golen. Gromenis. Rigios. Nimerix. Herg. Argilon. Okiri. Fagani. Hipolos. Ileson. Camonix. Bafamal. Alan. Apormenos. Ombalat. Quartas. Ugirpen. Araex. Lepaca. Kolofe. (= 32 spirits servient.)

However the Dehn note is as follows:
Aman, Camal, Texai, Kataron, Rax, Schelegon, Giriar, Asianon, Bahal, Barak, Golog, Iromenis, Kigios, Nimirix, Hirih, Okirgi, Faguni, Hipolepos, Iloson, Camonix, Alafy, Apormanos, Ombalafa, Garsas, Ugirpon, Gomogin, Argilon, Earaoe, Lepacha, Kalotes, Ychigas, Bafamal.

After a series of elimination you can deduce that Dehn’s Iromenis is the original Gromenis.

Beyond that, it seems the only mention is in Theodore Rose’s book Lucifer and the Hidden Demons. Because of this it should be noted that this is possibly pure UPG. Nothing wrong with UPG, but it does need to be tested properly.

So, in Rose’s book, he says the following:

For an increase in luck when gambling.
When you win at gambling, it brings an intense rush of pleasure. The ritual does not improve your skills, for games that involve skill as well as chance, but improves your fortune. Improved fortune does not guarantee a win, but if you are going to gamble, you would be a fool to absent magick from your activity.

Bring financial loss to those who build their success on your work, ideas or reputation.
When somebody has built their business by using your abilities, reputation, or even your name, you may wish them great harm. If you do wish to cause them harm for leeching off you, this power will bring many instances of damaging financial loss.