You need a commercial degreaser like Lipasolve 55 on coons, especially on large coons. You can only shave off so much fat on coons but then their skin is still full of grease that needs to be drawn out with a degreaser...and dawn won't cut it.
I concur,,dish soap is for dishes, a tannery degreaser is needed to do the job right, and it needs to be agitated out, just dipping the skin in like washing dishes is not enough. It will take a day or two in the degreaser pickle.