I'm going to guess that since the emulsion blew out and now the screen won't reclaim that it was underexposed. With some emulsions, underexposure along with a day or two of being dry can result in the emulsion becoming permanently locked into the mesh.
Give it one more try using a green scrubby pad and a lot of elbow grease, along with a power washer adjusted for high pressure and see if you can make some progress. If not, you might as well remesh that frame.
Give it one more try using a green scrubby pad and a lot of elbow grease, along with a power washer adjusted for high pressure and see if you can make some progress. If not, you might as well remesh that frame.