It may be blasphemous however there are other products out there apart from Shoe Goo.
I use Aquasure which is for repairing waders, inflatables and the like. It "soaks" into suede a bit better than Goo and is harder wearing, you don't get the goo scab peel.
I have used it on soles to varying degrees of success.
Stuff shoe with paper, invert shoe so its level, apply over affected area, lightly cover with masking tape to avoid run off, leave 24/48 hours.
After use you can freeze it so it stays fresh for next use.