Can you get a bale of straw or hay and a barrel of old fallen Autumn leaves?
Put them in the run area, yes make it all fluffy so they have something to dig around in. Have your brother toss some scratch feed in there twice a week.
Put PDZ on the bottom of the dog house and 3-4 inches of shavings, they will dig in there a bit and mix the poop themselves.
I would be MORE worried about the feed and water.
Can you post a pic of what you have now? If you don't have a self feeding container buy one that holds about 5 pounds of feed- Keep it in the dog house because of your rainy weather it's better. maker sure not to have one too big as the humidity in WA might make mold.
Waterer can be outside since you don't freeze there. Put it on a cinder block so tht dirt and stuff stays out of it. You can either just make sure they can get to it or do as I do, put it on 2 cinder blocks and then put 1 cinder block in front so they can stand on it to reach..... I have hens that kick the dirt/shavings EVERYWHERE !
Here is a pic from my security camera. You can see in the lower Right is the heated dog bowl for water. It's actually on 1 cinder block and a smaller wall block because I used the other cinder block for the feed..... middle to the Left is the feeder- self made auto feeder
The roost area is makeshift for this year, I was hoping to have a new house this Winter but it didn't happen so...I do have PDZ on there but only sprinkled on because I didn't put a piece on the end to stop it from falling on the ground. I did scrape it this morning.
If they don't roost then don't worry about it. But you may want to put a large diameter stick/ thin log, for them to sleep on. I think they like to have their feet on something.