I’m sorry you aren’t having much progress with her. Is the breeder or shop local where they could help you? Does Verde have her wings clipped? She will be much harder to work with if she can fly.
As to the perch, it sounds like it needs to be moved or removed. Some cages come with too many perches, some with only one. When placing perches, you need to make sure it is not under another perch or directly over a food or water dish. It sounds like she might be sitting on something above this perch and is pooping on it from there. Perches do get dirty, but it hasn’t been long enough for it to have so much poop on it unless it is under something else. Most birds do not like it if you use something like a cleaning brush when they are still in the cage. Birds will pick at their poop sometimes so it’s not a big problem. She probably isn’t actually eating it, but is picking it up our of curiosity. Parrots will pick up and even shred a lot of things without actually swallowing it.
Thanks for the update,