(intending to come across ignorant here okay?)

A grooming assessment? For real?? Youre judged on how shiny your bay horse is going to be? This actually happens? Is this a show horse, and you have to prove you know how to groom it or what? What if you flunk the assessment? Is there an actual grade???

All the advice given so far sounds great. Pick one or two and use them. If there is a grade on the verbal part of your assessment, make sure you meantion that its what goes INTO a horse that makes them shine. Cleaning them just puts the icing on the cake so to speak.