My mare doesn't have a stall, but she uses her 10 by 10 run in as a stall, she spends the night in it. She's a bit of a pig, or use to be. Now she backs into a corner and does all her business there, unless I wasn't able to clean it daily and than she doesn't want to go there because it's dirty already.
I put in about 6, 40 kg feed bags full of course sawdust from the local mill in her run in, bank it in the corner and sides. Clean all manure and wet out of the middle and push clean down at night. If we don't get a rain storm usually it lasts over a week. If there is a lot of rain and she won't go outside it lasts four or five days. Usually I don't have to strip her stall, if the good bedding runs out, I just add more to my bank.
The owner of the mill lets you take as much sawdust or shavings you want for $10, usually we get 40 plus bags. Or a packed truck load.