Ah yes, the freshly done poop.. A smell like no other. There is no surprise quite like putting your head into the vivarium to get your little guy out for a cuddle and get a lung full of the good stuff.
One time one of my geckos was walking around on my desk when he climbed on my keyboard, parted legs and left me a nice surprise poop right between the D and F keys.
Only their poop has an odor. And their food if they eat crickets (which is why we quit crickets and switched to the much more pleasant dubia roaches)..
I have actually sniffed my geckos a few times and never noticed any odor.. I wish my dogs were like that. Mammalian pets are gross compared to geckos.