I doubt these are much better or worse in terms of cleanliness than other airlines'; if I use the duvet or blanket, I use it below any flesh, so to speak (at least some airlines give you pyjamas; that helps too). For me to consider carrying something, it must be lightweight, very portable, multi-use. And many aircraft cabins are too warm to use the duvet.

Google "travel blanket" and you will get many options, including these:

Eagle Creek Comfort Travel Blanket ($19.85) <link>
Microfleece, 59 x 35½ unfolded; 11 x 10" folded; 10 oz, folds into its own pocket, which can hold small items while you sleep in it.

Magellan's Luxe Travel Blanket ($24.95) <link>
54" x 49", 12 x 10½ x 3" in pouch; 19 oz. Foot pockets, large zippered compartment for items, attachment strap. Machine washable, static-free ComfortControl poly, folds into its own zippered pocket.

Travelsmith's CoolMax® Travel Blanket ($30.00) <link>
3 1/2" x 7"; opens to 55" x 70", stows into stuff sack (about the size of a drinking glass).

Magellan's DreamSack Travel Blanket ($39.85) <link>
Silk, 72 x 43"; 13 oz, fits in small travel pouch, and can be used as a pillow.