what have y’all used to stop mane chewing?? Can’t put it in a bag like a tail....I have rap last but that stuff burns my skin so I imagine it would burn the horse too. I thought about hot sauce and soap...any other ideas?..

Do said horse(s) have access to salt and minerals as required? Or is this a boredom behavior?

Free access to salt/mineral and hay. I have a feeling it’s my 2yo reaching over fence as I saw her scratching his back across fence the other day 

Then consider separating them.

I have used Zatarans Crawfish Boil on tails before to get them to stop.  It will burn your eyes but deters them from chewing.  Not sure you would want to use on a mane tho?   Other option is to place hot wire between the two pens.  Likely your two year old is doing out of boredom.   Good luck!

I am fighting the same thing with my weanling.  She chews on manes and tails.  Another weanling and a babysitter are in a 5 acre paddock, ton bale of hay in a feeder, access to loose mineral and salt.  I hung a lick tub on the fence to see if that would occupy her and I think that helped.  I tried mixing cayenne pepper with Vicks to put on the tails...didn't stop her.  Boredom is the worst.....I was hoping it was something she was missing but it doesn't look that way. 

Spray it with WD 40. They will quit chewing on it and it won't hurt them. Also it will help detangle and shine up the mane. Yes it really works.

Snoopyjoe...hadn’t heard that one for chewing, but will definitely try it! Love it for bad tangles.

If you use the WD-40 dont use it if horse is out in alot of sun, it will burn the mane and make it brittle. 

I have had good results with rubbing alcohol and hand sanitizer isn't real tasty either. I have a couple of weanlings that line to chew. One likes manes and one likes tails. What a pain. They get Platinum so they are just bored. 

I do have a suggestion. Before you decide to put Cajun season or other things that you aren't sure if it will irritate. Put some between you legs and go out and feed. If it does burn or irritate, you're good. I know that I have one mare that swats her tail between her legs and under her belly. I know she would be a little put out if I salted her tail with anything that burned.