Nice, full, thick Mane and Tail questions

Yes, I usually condition every time I hose them off. Helps to keep the hair moisturized and prevent itchiness and breaking.

something out of the dollar store might actually be ok to use as far as a conditioner to use maybe once a wk or so ?

Yeah that works. Thwere are products you can buy but juist give it a good deep condition about every 2 weeks. Then yu should be ok. SDome horses Like this one horse at my barn Jamie Her tail is freaakishly thick I mean like if someone gets nervous or needas to like think about someothing for a while they sdhould just go brush Jamuies tail. There isnt really anthing you can do but if you leave it in braids I the winter and then take them out it gets really wavy and poofy.

about 5 minutes of letting the shampoo/conditioner set in the hair then rinsing?

I spray a moisturizer/detangler on my mare's mane and tail daily and finger comb out the tangles. I use either Healthy Hair Care Moisturizer, which is made for horses, or Infusium leave in treatment, which is made for humans. Both are relatively inexpensive and don't need to be rinsed out. I apply these while she's eating so it doesn't really add any additional time to my daily routine. I also wash and deep condition both mane and tail about every other week in the spring,summer, and fall. When it's muddy I keep her tail braided and bagged to keep it cleaner and tangle free.

can any of those things get on the horses skin without causing any irriatation or do you have to be careful to spray the hair only?

kinda off topic here but WOW your sturrups are all jacked up in this picture! Please tell me you do not ride like this!?

Neither one should cause any irritation to the rest of the coat or skin. I actually spray my mare's whole body with the Healthy Hair Care Moisturizer to keep her soft and shiny :)

Yes, you can use a spray in conditioner like Best Shot's Ultra Vitalizing Mist, that's what I use and LOVE! Not greasy, and I use it in MY hair, too! It nourishes it, but also is a great detangler.

I guess I'm lucky. My girls have very full mane and tail. Tail hair almost drags the ground, but I'm sure it's the result of their Friesain blood since Friesians are noted for having long, thick mane and tail.
Comes at a price though. Need to run my fingers throught it periodically and work the little tangles out so they don't become bigger knots. There are times it's tempting to thin it out, but then they wouldn't look right to me. Never had horses with so much hair.