Reclaim a screen I screwed up?

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.

I have had good success by using degreaser on the hard emulsion (stencil remover wasn't touching it), leave for 15 mins then wash out with power washer. It washed away quite easily.