I prefer to use my tongue but there are a number of commercially available liquid soaps designed specifically for cleaning a horse's sheath and cock. Never use any antibacterial soaps.
Yes I do worry about being kicked being this horse is a bit of a bully over the female, but it would be my 1st chance to actually touch a horse cock & it needs to be done, So I figured what a great excuse but watching YouTube videos it dont seem to be such a turn on, but being owns horses I found my opportunity to finally touch one. * being its a thing that needs to be done I'm offering to do it.
Yes I have been watching the videos & even non-sexually want to learn a take care of her boy, seems it should be cleaned every 6 months to a year & she has had him at least 2 years & has not been doing it, & being I'm perv & also if it needs to be done & she he's not been doing it, I will & then from there maybe we can play with him?
"we" can play? umm.
Do not go there. She does not want to touch their bits for her animal's health. Keep the smegma to yourself.
No idea about horses but two years look a long time. They could have some big bean to be taken out, irritation, etc.
There are users here who are in animal rescue and could give some good advice if they wished, but they are also quite happy to set in dumpster fire flames users with messages like this
What I would do is, next vet run, explain the situation, that you want him/her to do the cleaning, check everything and show you howto so you can mantain them from now on.