This doesn’t really matter for the sake of this discussion but I feel the need to point this out so you can better understand why you don’t like silicone - silicones are not directly responsible for drying out, although they’re directly responsible for other things. Silicone coats the hair for a quick, easy and temporary shine, can attract dirt, but most importantly for this discussion, silicones are not water soluble, so they stay in the tail until you use a relatively harsh sulfate-based shampoo to remove them (most shampoos contain sulfates) and that’s what dries the hair out. Therefore silicone products build up over time in the tail unless you’re doing shampoo baths.
There is nothing wrong with silicone-based sprays if you understand how/when to use them. I follow the no-silicones Curly Girl Method for my own curly hair, but don’t find silicones as troublesome on horses who have thicker individual hairs and a more closed hair cuticle, at least during the summer when I give a bath with shampoo and then follow that up with GOBS of conditioner every 4-6 weeks. I do avoid them in winter. Pic of my horse’s genetically blessed tail so y’all know what I’m talking about 