Along the lines of what others said. If your going raise your own rodents you need be prepared to spend as much...or MORE time on them than your snakes. Regular cleaning is the best way to keep smell down, along with the little tricks folks mentioned above. You don't have to touch them all that much if you choose not to but when you clean you have to get them out somehow.

You may consider african soft-furred rats, between weekly cleanings they have virtually no smell. However they do not reach the same size as common rats and if being scared of a nibble...or full on bite is an issue you may not want to try them.

Either way if you have an issue with rodents you probably should not raise your own. As I said you need be able and prepared to put just as much work and quality into their care as you would for any other animal as your snakes health, depends on their health.