OR: How to give your horse a hand job.
Read this in a joking manner unless you really do need to know how to clean your horse's cock. Then read it in a serious voice.
Horse sheath cleaning is very important. Just like a normal man should probably attend to genitalia hygiene at least once a year, you should attend to your horses' genitalia at least once a year. Stallions and geldings both need their penises cleaned on a regular basis but stallions are kept whole to have sex and so they get their cock cleaned at breeding season anyway. It's geldings who have the issues and if you have a gelding you need to clean their sheath and penis. It is suggested you do this every two or three months but six months to a year is also common.
When a male horse is pissing or is relaxed he will stand with his cock out. This is when you should check the skin for flakes, oiliness or otherwise unsavory appearance. If he has any of this, or if the horse is having trouble pissing you maybe need to clean the horse's cock.
You'll want gloves. Short finger nails and latex gloves. Nothing to do with the horse's comfort or hygiene. Do you want your fingers to smell like horse dick for a month? If that's a yes then cut your finger nails for the horse's sake and wash your hands, but don't wear gloves. Horse bits smell yummy when it clings to your hands and you're eating a sandwich...
First, a bit of horse safety: In my experience, no horse is happy with you playing with its cock. Just because you know how often your gelding gets rejected by the ladies doesn't mean that he wants his human to feel him up. Tie him with string to something solid, so he can break the string if needed but is secure at all times. Yes, I said tie your horsie up. Alright, now you are thinking you must rape your horse but truly this is for his own good. No, really, it's for his own good.
Also, stand very carefully by your horse. You will be working at his back legs and back legs kick the easiest. If you are right handed stand on his left side so your hand can reach him the easiest there. Be ready to jump out of the way at any moment.
Use Betadine soap, mineral oil or K-Y jelly. Betadine needs rinsing afterwards, so beware if your horse likes to run amuck. Mineral oil is a bit messy to clean up and K-Y jelly needs no rinsing and is generally easier to use as it is a lubricant.
Now, get a hose with warm water. No horse will be very happy with a jet-force spray directed immediately between his legs so use a very gentle spray and run it over his legs. Start with the front hooves and work slowly up the leg. Then move to the back hooves and work up to the hock, along to the stifle and to his sheath. Wait for him to relax a little and move the hose around across his belly and legs, as well as on his sheath. Do not expect him to let you see his cock. Once he does not flinch with movement of the hose very very gently work the hose up his sheath but do not force it in too far. This is as much of a test of your horsie as it is a gentle washing. Use your (gloved!) hand to massage him a bit to help it in. Be very careful of his feet at this moment, he may try to kick. If the horse gets upset go back to the hose on legs/flank/belly until you can do this. If there is no way he is relaxing with this then stop and move on to the actual cleaning part, but do so with infinite care.
If you are using the Betadine soap get two buckets and two or three cloths. Not towels, Chux and other wash cloths works great. Soft and thin but they can soak stuff up. In the buckets put warm water. You would not like some thing from another species shoving ice water at your dick, so do not do it to your horse. I say two buckets because horses like to kick things over. If you have only one bucket that one bucket shall be kicked and cracked. Since you have two nothing shall happen to either but it prevents you losing a single good bucket. Put a lot of the soap in there and mix it up.
The jelly can be used in your hand, ensuring that it is smeared all over your (gloved!) hand; I would suggest using the wash cloths for the oil and the Betadine. This is the fun part, giving your horse a hand job! Rub the cloth around the sheath and then push it inside. Feel around a bit inside of there and rub it all around. Be very nice and massage your horse. Re-soak your cloth every so often and get some of the gunk off. You may need to use a second cloth. You may also need to put your hand into the sheath to scrape away the ikky bits horses accumulate around their dick.
If you are lucky your soft massaging hands will cause your horse to relax. This is a good thing, not an embarrassing as you can now give your horse a better hand job! Take his cock in your hand and rub it in a soothing way with the jelly or cloth. If he pulls it back in be ashamed as he does not want your attentions, and go back to rubbing his sheath. If you get a hold of his penis then carefully insert your finger into the end and dig around in a stimulating manner. There is a pouch at the tip of a horses penis that can catch dirt and make life uncomfortable for the horse.
When very little dirt is coming off use nice, clean, warm water to rinse his cock and sheath. Remove your gloves and give the horse a treat.