First, bless you for taking care of Wid. Sounds like he needs a good home.
Does he scratch and his skin and chew his feet, or is it just the discharge and itchy ears?
Please keep after his ears. Once they develop chronic ear infections that can become a lifelong battle.
Also, if he's itchy, I find Aveeno oatmeal baths work. Another member told me you can use regular oatmeal as well. (cheaper). Also, I wash Gingers face with aveeno baby bath and shampoo. Helps keep her eyes clear and the gook away and doesnt hurt her little eyes at all. Vacuum, vacuum, vacuum. Wash his feet (with baby wipe, damp washcloth or good old running water) when you bring him in to remove residue from the yard. Change your furnace/ac filters regularly. You can also use benedryl if it's severe, search for correct dosage. You may wish to research that as some prefer to avoid meds altogether. I prefer for my girl to be comfortable, so I have succumed to the benedryl (and occasional stronger meds from the vet).
A high quality diet is a must. You might try switching to something with a less common protein source (white fish or lamb) and with no corn, wheat, or corn/wheat byproducts.
Good luck!!!