Yep i reckon I could demolish that after the 100 SZ
No I have never had a problem with using Cornflour on my feet..
The theory as I understand it is that most foot powders are mineral based i.e. ground up rocks and therefore conductors of heat which means that after a while they are abrasive.
Whereas Cornflour is vegetable based and as such removes heat and does not become abrasive.
Well it works for me and quite a lot of other Utra runners.
Enjoy the break from a long run SN, for my part i will stick in one more reasonable effort before the off