How do you refresh your LR3?

I've had my LR3 for a while now but I'm looking for new ways to keep it "refreshed". I do a deep clean on it once every few months, as it never really gets that bad but there are often litter smears on the ceiling part (it's always litter though, and not pure feces) and I like to keep it refreshed.

So far I've been wetting a paper towel and wiping it down with warm water or warm water + dawn dish soap and then drying it with another paper towel. This works fine I guess but I noticed that Whisker also sells their own wet wipes for the robot and was wondering if these were worth it? Or is there another way people keep their LR3 refreshed?

I'm also still hunting for a litter to use that doesn't stick to the rubber liner or smear on the ceiling as much. I've tried so many, Dr Elsey's being one that I used and really did not like (but seems to be quite popular) and have currently been going between Fresh Step and Arm & Hammer Slide but neither have impressed me yet, same goes for Whisker's own litter, unless the smearing/sticking is inevitable.