Scaley leg mites will raise the leg scales on your Rooster and also leave grey deposits on his legs....treatment is easy and effective.
Soak his legs in a solution of epsom salts..(or soapy water) for 15-20 minutes..this will loosen the deposits, you can also use a soft brush to clean his legs..dry his legs thoroughly and apply a liberal amount of vaseline (up to where his feathers start on his legs)...repeat treatment weekly to ensure problem has gone...it is prudent to treat ALL of your chickens for this problem..despite none of them showing symptoms at the moment.
Wear OLD clothing when applying vaseline..it is a mucky job!
No..DE will not work...you need to treat with the simple and cheap suggestion I mentioned above.
DE is not an effective solution for lice/mites nor scaly leg mite problems....
The vaseline will also ease his bleeding legs and protect them from further infection...it would be a good idea to use a weak solution of betadine when you are soaking his legs...it will help to keep a bacterial infection problem from causing further problems.
I wish you luck and vaseline free stains on your clothing!