I use Healthy Hair Care moisturizer to cut down on dust clouds when grooming. It is the only thing I like b/c it is basically only oils & lanolin. An added bonus is that the price is nice & it lasts a long time since you mix it yourself. Before I curry I do a light spray, then it gets rubbed in. I also use it in the winter right bf I put on blanket to reduce static.
I do use dollar store spray with silicone for detangling tail and mane.
To echo what everyone else has said, you can’t have shine/bloom without a good diet. Genetics places some limits. Beyond that, you can help it along w fat in the diet and elbow grease to get to maximum gleam. Regular currying brings up the oils, then soft brush/rag lies the coat flat for a nice shine.