His advice on gods fits in a miscellaneous chapter and amounts to: only idiots deal with deities, stay the fuck away.
The 19th-edition annotator of The Dungeon Anarchist's Cookbook wrote what little the book has on deities, stuffed into the middle of the miscellaneous chapter. He lists the three summoning types — Celestial Boon, Indentured Summoning, Involuntary Summoning — and says to avoid all three. He explains that some gods are genuine NPCs but the big ones like Apito and Eris are sponsored by rich pricks paying to play The Celestial Ascendency on the twelfth floor, that gods are invulnerable below that floor, that they are strong, that they kill everything, and that there is not a damn thing anyone can do about it. All three summonings, he writes, lead to the summoner's death — even the voluntary one.
A second note by him focuses on involuntary summonings specifically, the kind Carl's gauntlet causes: a common enough occurrence, and a revenue stream, since god-summoning equipment is sprinkled through the dungeon to allow special guest appearances, with the deity slots often bought by celebrities who are not part of the dynastic families controlling the ninth-floor armies.
Cookbook annotator and the source of everything Carl knows about gods.