I also use Just for Men,,,,,,,,,,,the color is called, Almost Black.
I put an old blanket on the horse, and an old mane tamer.
Both now have slits in the correct places.
Am still using the original ones. Let it dry, use it again.
The blanket and mane tamer was made to fit the horse, already has the hardware to keep it on the horse, I just added the slit.
I made sure they were cotton, cloth,,,,,,,,,,,,it then absorbs any drips. Plus the horse is use to wearing these things.
Just wanted to add. Do not make one long slit to pull the mane through. Whatever you are using, the one long slit will make it gape open. I have 4, 4 inch slits up the mane,,,,about an inch of material left between each slit, helps to hold it there,,,,,,and then can get all the mane pulled through those 4 slits. May have to do a very small tough up at the base, but very small.