Everyone says to rinse 2-3-4 times a day, but I'm just letting you know that you can still get a shaggy calf with a healthy coat just by rinsing once a day, and without a cooler! That's all my parents allowed me to do and I always had calves with shag and everyone just assumed I had a cooler.
Every morning I would bring her in the barn, blow out all the dirt and spray a 50/50 kleen sheen/vinegar mixture. I regularly added a few oz of rag oil to replenish her hair. Work that into the hair and then the was then fed and let loose in a stall probably 16x16 with 1 fan for the day.
I worked from 8-5 so my sister would usually clean up the pen during the day, but didn't ever brush or work hair.
Mid evening I would rinse for probably 10-15 minutes, set a fan behind her and brush all her hair forward. I usually tried to work a roto brush through her legs and her body occasionally. I used a women's paddle type hair brush more than anything though. I would then blow out any excess water and hit her again with the kleen sheen mixture. She was fed and then let out about sunset.
She was fed AAOK's ration, Sure Champ and I added to some kelp meal, which is supposed to help lower the internal body temp.
I started this regiment on a fairly slick shorthorn heifer last June and had a decent coat in 45 days, and a nice thick coat by state fair in mid August.
I only soaped her about once a week, and used revive for 1-2 days after a show.
As RSC mentioned, that shedding comb is awesome! It works great at getting all the dead hair out.