Hi Josie,
I would not recommend any product that isn’t made for pet birds. What kind of cage do you have? Most cages have a metal floor grate that keeps the birds away from their poop. Is your cage large enough? For two budgies, a cage needs to be about 20inches X 20 inches, and square. A round cage is not good for birds, and a tall cage isn’t good. They do not fly up and down, so with a tall round cage, most of the cage is not used. You are correct to never use any product with sand or grit – do not ever feed them any sand or grit. It will eventually impact in their system and kill them. The cage should be cleaned daily, so cage liners can get pretty expensive. Plain brown paper that can be bought in rolls works well. If the cage has a grate and they can’t reach the bottom, then newspaper is fine. Or you can buy unprinted newspaper at an office supply store. You can also use natural Aspen shavings with nothing added. Do not use any other types of shavings. If you use brown paper or unprinted newspaper, you can cut it to the size you need and put a week’s worth in the cage, so you remove the top layer each day. Then you can do a more thorough cleaning once a week.
Thank you for asking Lafeber,
Brenda