I went with Iosso for its nonpetroleum base and ease of application. According to Iosso email response, no effect on vinyl or window mesh and the Sunbrella properties. I simply put it in an old Roundup spray bottle and fine misted the ?$#@% out of the Sunbrella 2 coats around the pullout windows. Some was absorbed and some beaded on remaining 303. Just let the excess run off onto the driveway and wiped off the overspray and drippage from the vinyl and window netting. It cleaned the vinyl nicely except for the old 303 runs. Cost for 2 gal + shipping was $100, about half the cost of 303 in my area.
The Bad News: Water tested the canvas for 1/2 hr with a hose when cured. No leaks. But last nights thunderstorm resulted in the same old leak (about 1/4 of a paper towel wet) in the downhill bed corner. Somewhere water is coming in and running horizontal to the corner. I'll try Iossoing the window flaps next and look for a pinhole somewhere. Wish me luck.
The Good News: Found a nut on the camper shell when looking for the leak tonight. Turns out it came off a pullout roller. All my rollers are loose! How to remove the rollers will be another thread. The good news is it happened in the driveway and not in the woods somewhere.
I won't add anything more to this thread, but will leave it on my monitor list in case there are any responses.
I have never had an issue with Kiwi Camp Dry and have found it to be a good product for the money. I know people swear by the 303 now. Has anyone here had an issue with Kiwi Camp Dry damaging their canvas?