If you have a drainage problem then nothing on earth will fix the mud problem except to fix the drainage.
If you do not have a drainage problem then adding plenty of dry organic material as bedding will do the job.
There are a number of threads on mud in the run that contain considerable information to help you figure out the best option. You can find them by doing a search.
For immediate, short-term relief, try putting down some pallets and intact straw bales to get the chicken's feet out of the wet...