Waterproofing Canvas

Has anyone got any tried and tested methods of cleaning (green mould) and waterproofing canvas tilts?

No idea about your mildew, however I've got an ancient canvas tent and when it has needed re-waterproofing in the past I've managed to get an aerosol of waterproofing agent from Millets .... I guess canvas tents aren't quite so proliferous nowdays so you may have to go a little further afield. Seemed to work well.