Foster cat smells funky a month later… how do I make it stop

Hi everyone! My partner and I have been fostering the sweetest kitty for a month now. She likely came from a hoarding and dumping situation with multiple mats so bad many had to be surgically removed. She smelled quite horrid when we got her and we assumed it was the mats. The rescue gave us pet dry shampoo and the mats were removed a few weeks ago. She still smells funky though. I can’t identify the smell but it’s noticeable and I worry it’ll turn off people wanting to adopt her because she really is the sweetest cat. Anyone have any suggestions? Do I just routinely use the dry shampoo? I know it’s bad if I still notice it and live with her. I do not feel comfortable giving her a bath as she’s not my cat.