OK, I answered my own question. I bought the mane & tail brush and it’s great. A bit more work than just spraying on some detangler, but well worth the effort. My pony lives out 24/7 in dirt/mud and loves to roll. His mane is long, past his neck and white. Detangler was last used a week ago so there’s really nothing in his hair now. It came out white and sparkly shiny and feeling light and natural.
I’m hoping to use this brush year round, but I fear that it will create some static electricity; my pony is NOT a fan of that. I may give the brush or mane a spritz of something then. The detangler used before is Manely Long Hair, which I loved before I bought my second bottle. It now seems thicker and makes the hair a bit sticky so I won’t be using it anymore. I’d love it if I never needed detangler again.
His tail also came out nice. Much easier to twist and do small sections than the mane.
It’s amazing how the right tools work so much better. Grooming is so much more effective and more fun and satisfying. My pinto pony’s white areas are soooo white and there’s not a hint of dust during a “poof test” (patting the hindquarters).