I'm kinda a skeptic when it comes to "RV" products, often just household products at twice the price. My seals are simply rubber and I'd be tempted to use what I use on the rubber roof, which is spic & Span powder. (Surprised? It's exactly what the rubber roof manufacturer recommends!) http://www.alphasystemsinc.com/royalepdm.htm
I'd be a little leary of bleach, although a small amount is sometimes recommended by A&E for claaning awnings. In fact the best product for cleaning awnings is Tide liquid with bleach alternative - which might be good for your seals too.