Wiper blades are one thing that are more or less the same (Save for size) no matter what you drive, so what works on a Mini-Cooper works on a 40' class A DP (Ok, so the Mini's wipers would not FIT on the class A but cleaning, replacing, what to replace, and the like, are the same)
There are several products on the market that promise to restore your wiper blades to "like new" condition Various wipe ons, cleaners, and the like... So far the only thing I have found that actually makes them "like new" is... New blades (The rubber part)
Replacing the wiper blades on my towed.... I suspect it will be cheaper to replace them on the MH, (And you know... not that much different in size) Replacing the rubber is much cheaper
Ont thing to remember though is there are a few different failure modes
1: Rubber worn out, or dry cracked or otherwise failing (Replace rubber) (Done this many times on assorted vehicles, not yet on my MH)
2: Blades (The springs which hold the rubber so it can conform to the windshield) have lost their springness and need to be replaced, (Replace blade) (Done this a few times too, also on assorted rides not the MH
3: Arm, like blade, can also wear out (Replace arm) Did this once, Mercury Rracer 10 years old
And that's just the easy stuff