A well made mecate needs very little actual care. Just using them is the best thing.
Many horses who never chew on halter ropes will, for some reason, chew on hair. If a horse chews them, or pulls back, the rope can be stranded. This means one of the strands is broken or seriously damaged. Stranded ropes must be replaced as they cannot be repaired.
When tying a manehair mecate on a snaffle bit, we suggest being very careful when pulling the rope through the slobber straps. If you pull it through quickly, you can strip the cover strands right off the core. This is especially a problem if the holes in the slobber straps are smaller in diameter than the mecate.
All of our slobber straps are made with a 5/8" or larger hole, but other makers don't necessarily do that. If the holes in your slobber straps are smaller than your mecate, take them to a repair shop or return them to the maker to have larger holes punched in them before ever trying to tie up your rope.
Once you are sure the slobber strap holes are the proper size, work the mecate through them slowly, twisting it as needed to move it through the holes. Measure off your rein length and tie the lead off at the left side.
Now hang up your bridle and stand behind it as if on horseback. Try to throw a coil in the loop rein. If the rope is trying to make a figure eight instead of a coil, you need to work a little twist out of the rein. In working it through the slobber straps, a bit of twist can be added. This is normal.
To get rid of the extra twist, just turn the knot slowly one way or the other, depending on which way the extra twist went in the rope. Keep trying to throw a coil. If you're getting closer to a coil than an eight, you're twisting the knot the right way. If you now have a couple of figure eights stacked on top of each other, you've been twisting the knot the wrong way. Keep adjusting until you can form a smooth, easy coil.
If you get the mecate wet when its tied on the snaffle, do not take it off of the bridle. You run a serious risk of kinking it or stripping the cover strands off of the core. Just let it dry out naturally still tied to the slobber straps.
This is safe with one of our mecates or with one you know is 100% mane hair, but not recommended for a mane hair/tail hair blend mecate. When a mane hair mecate gets wet, it will get really stiff. This is caused by the twist contracting. Any rope made of animal hair will do this; mane, tail, mohair, yak hair, cow tail, or alpaca, just to name a few. The interesting thing is that when the rope dries out, it will be softer and have a nicer feel than it had before.
This gives the rope a whole new look and feel. Nothing is prettier than a rope that has been worn smooth. However, don't try to hasten the process by trimming or clipping the hairs. Long hairs wear off faster and easier than short ones.
I personally don't think they should be washed, but it can be done. If you must do it, here's the best way: