Had this last year with a custy. A bird fell down the chimney and flew about crapping everywhere. The little blighter had eaten berries (as they do) and pooped all over the sofa and chair leaving purple stains

We hoovered off the worst (it was dry

), then cleaned with pre spray and brushes, then towelled and finally HWE. Most came out but not all. We resorted to HP @ 6% which made a small difference but still some left. We managed in the end to get it all out with Specialist Stain Remover from Alltec and some perserverance.
Custy was delighted, not only did we get more work from him but he recommended us to 3 of his friends who we did suite cleans for

Good luck!
Kev