Rain proof a DPM Smock

[Big Stu 12]

I have got a DPM Temperate Smock that I would like to use more in the less dry days when there is the odd shower, I know that you can reproof them, with does anyone have any ideas what would be the best Product to do it with?

 

[Limaed]

Greenland Wax works reasonably well, just rub on then iron: http://husky.uk.com/Fjallraven-Greenland-Wax