MTG has always worked for me.
Please be careful when "scrubbing" the scabs off. It'll hurt like h*ll if you just pull them all off. I use the MTG to moisten it and soften it and you can slowly rub it off but I wouldn't just grab a comb and have at 'er.
As per bacon grease - I've never used it before, never heard of it being used for rain rot but an old cowboy once told me it worked wonders for cuts that were producing proud flesh as the bacon grease attracted flies which then ate the proud flesh down.
I don't know if it works or not but thought I'd throw that out there!