Certainly, you can also use Power Cleaner on cotton and canvas tent cloth.
However, we always advise testing on a small, inconspicuous area first. Power Cleaner may fade some types of tent cloth slightly.
We use it in our specialist sail and tent cleaning facility to clean heavily soiled cotton folding trailer tents, tent awnings, boat covers, umbrellas, sails and sun canopies.
Example of a cotton tent cleaned by Ultramar Sail & Tent Cleaners