I just cleaned the canvas on a Prince 16" print dryer, by removing it from the machine, spraying it down with a stain remover "Shout" and after letting it sit for about 10 minutes, soaking it in cold water with a 1/4 cup of Clorox Chlorine Bleach for 15 minutes.
I then pull the the canvas belt out, layed it out on the sink flat and scrubbed it with a very stiff scrub brush, trying to push the soap suds through the fabric. A lot of crud came out of the belt, and it turned a uniform yellowish/orange/brown color, yeech.
I then spent the better part of 45 minutes dunking the belt in a tupperware storage container full of cold water, rinsing the dingy crud, soap and bleach out of the canvas and dumped the water many, many times until no color or suds appeared when I plunged the canvas into the water.
After that, I rolled the canvas up tightly in a towel and put some strong rubber bands around the roll while I cleaned the chassis, oiled the chain, examined and polished the drum with a soft cloth and cleaned the bearings on the transport system of the dryer.
When ready, I installed the canvas back onto the drum and it was TIGHT! Kind of panicked me initally that it barely would fit back on the drum with all tensions at bare minimum, but once I got it back on barely enough to run, I turned the dryer on and as the heat dried the canvas, it stretched back to normal size.
Interestingly enough, the dirty brown cast to the canvas slowly changed to a much lighter shade when fully dried in about 20 minutes of running at full heat.
The canvas still has stains, but they are not so obnoxious, the fabric feels softer and the drier certainly runs better after I clean and lubed the drive system.
All in all it was worth it...
Now, I have an HUGE Arkay and another Premier to do when I get time!