daughter had a white steer last year, keep the pen clean first, not always easy, but oxy clean and also baking soda detergent- peroxide paste use gloves strips the oil out of your hands then condition him/her.
I forgot to mention with my original post that when we use the laundry detergent we mix it 1/2 and 1/2 with water in a smaller bottle. Sorry about that!
Looks like you have a ton of products to give a whirl. We have had some white one's over the years and like they said, you have to keep their pens exceptional clean. The liquid oxy in the bottle that you can spray works great if you leave it set. Caution with the bluing as they can come out with a blue tint. Ever see those little "blue haired" old ladies.
We spray our brown spots with hocus pocus about an hour before we wash and it helps cut the stains. You may have to use it a couple of times before you see a major difference
We use Lemon Juice on our Chars. Works really well. Spray some on when they are wet after soaping,,,let it set a bit and then rinse. Take few washes to lighten, but doesn't dry the hair to bad, and works well
We've always used the same products we use on our lambs, as far as detergent and the "Bright Light". Like the above posts have mentioned when you use the bright light I suggest only using it on showday....put it in small amounts and leave it there no longer than even 30 seconds, we put it in one spot, move to another and then quickly wash the first. Hope all these tips help. Good luck! Those white's can be a pain in the rear but are always look classy in the ring!
gojo and horse soap that you get at tractor supply and bed on pine shavings i have a white shorthorn she gets washed 5 times a week and worked for 4 hrs a day and she is white as snow