How do I clean my canvas bag?
As well as for the saddles, leather on bags and backpacks should be kept supple.
The best advice would be to use products specifically for the cleaning of leather bags. Using Proofide to clean your bag can work as long as result in a very noticeable darkening of the leather.
How can I re-wax my canvas bag?
It is a common feature for canvas fabric to show marks and fading colour with everyday use: it is the distinctive trait that allows to make every backpack unique.
Although it is not possible to bring the colour back to life, you can protect it from fading fast. You can use any fabric wax as long as it is just a rub on one.