Some pictures are ‘dirty’ when apply to full body photo, is there a way to improve it?

[Folkfive]

Hello, your work is really great. I try to apply the filter to some full-body photos. But in some pictures, they look dirty in some parts. I find another app that may use your work, their results look much better, and the pictures are 'clean'. Do you have any ideas to improve the results? I uploaded the results and the original picture I used.