Sorry if this isn't helpful, I got a little confused about the question
Try to only remove the bedding that smells or is yellow, instead of just taking out all the bedding or half of it.
I think the best way to reduce smell is to have more bedding. While my past hammy did pee more then Eric, I think that now that I add 10 inches of bedding it has been a really big help with smell. You can also try adding some hay that smells nice or some aspen bedding. Adding plenty of flower forage can make the cage smell really nice too.
The food situation sounds frustrating. It's nice of Kikya to send you some to try! I hope that you can find a good food soon.
Hopefully this could help!
