Is there such a thing as a spray in, leave in conditioner?  I would like to regularly condition my yearling's tail through the winter, but I don't have a blanket for him and therefore I don't want to rinse his tail regularly.

Also, is there a spray in, leave in shampoo (yay if there is!).

Thanks for all answers!

 I use people products on my guys (and girl now, I can't keep saying guys...) and it works pretty well as far as shampoo goes but...I like to get simple detangle sprays and spray liberally on tail and mane.  It isn't a conditioner, but it does help even things out.  I've tried a few detangle sprays but the best one I have found is Mane and Tail.

http://www.healthyhaircare.com/hairMoist.php

Just get a cheap bottle of VO5 conditioner and brush the tail out, rub in and brush through.  I also braid it afterwards but you dont have to .  I do my horses tails like this probably once a week, sometimes more and they have soft tails that grow fast and are eas to brush through.  For only $1.19.

If you mix it down with water you could put it in a spray bottle and use it as a spray in.

 http://www.kotrading.com/shapleys-mtg-2.aspx

 Wards away wintertime fungus and dandruff while promoting healthy scalp (do you call it a scalp on a horse? lol) and increasing hair growth.  great stuff!  Also good for "itchy" tail!  but beware... it smells like BBQ! 

Show Sheen!! Spray in, brush out.. Plus when I was a kid and I would cry to get my hair brushed we used it on me too... And Mane N Tail. I use it on my hair now, and it really grows fast! Its pretty cheap too, no need to rinse.

Romeos Klassic DJ:

Also, is there a spray in, leave in shampoo (yay if there is!).

There is a dry shampoo for horses, I think it's called Dry Radiance (?). It's kind of like a powder, and you put it on the horse's coat and then curry/brush it out. When I lived in Chicago, we always used it int the winter -- it would clean the horses' coats and help absorb some of the sweat. I'm not sure if it's available online. We always bought it at the local tack shop.