I wouldn't advise doing this, just because I don't know what long term effect it would have but...
I used Clorox Kitchen Cleaner w/Bleach on my old pop-up and it did wonders. Sprayed it on and let it sit. Used a plastic bristled brush and some elbow grease. The canopy turned out beautiful with no ill effect. Some people will cringe with the word 'bleach' but hey...it worked.
Just use good judgement. Maybe spot test somewhere inconspicuous.
2013 Jayco Eagle 328 RLTS
2012 Ford F250 6.2L 4x4 CCSB W/Air Lift air bags
2002 Coleman Bayside Elite (traded)
Me, Momma and Charles (RIP buddy)
And introducing Sofie!! ;)