Do it. Just make sure to take care of your feet. Blisters suck, and running again on just healing blisters sucks more. Vaseline all over your feet before putting on your socks, or use this stuff. It's magical. I did 50 miles at WTM liberally applying this stuff. My knees were toast, but I got absolutely zero blisters on my feet.
I haven't heard of GurneyGoo before, but the fact that it is durable on the body is great news. I see Amazon has it.