Laundering tent ends. Am I crazy?

Would not even consider removing the tents and trying to wash them in a machine - I could see a disaster in the making. I have no idea if this would work, but in the days of the old canvas tents, they used to use Fels Naptha and a scrub brush. It's not available everywhere, but our Walmart does carry it. It's a big bar-soap. The downside is that you're going to have to rinse it well. Are the stains just here and there or all over?? If it's just spots, if the Fels Naptha takes off the stains, I always used Woolite and water to clean the inside of ours. It did a good job and I wasn't concerned about a bleach product ruining the canvas to the point of having to replace.

You might also call one of the companies that do mold/mildew removal and see if they have any thought....other than hiring them to do it, of course. Good luck...hope you can get this fixed.