No don't take his foot off. You might need to lance any new swelling or "blister" and let it drain. When the infection is new, it is still liquid and drainable. But I would just let it start to dry and heal, left uncovered. I have used a dry powder called Wound Powder (or something similar) that I buy at the coop. It's for flesh wounds in animals. Once I've cleaned and treated and/or stitched up a wound I'll powder on a nice thick layer of the black powder and it helps to dry and heal. I may can post later today the actual name but the bottle is out in my tack room.
Monique
Monique