Kenkotherm comforters are Dryclean only.
Not a good idea. Water can fade the color, and change that nice texture.
Just look at the care label.
Getting a comforter cover means that you wont have to wash your comforter as often as you otherwise would have. for people who have down comforters that are dry clean only this can be a god send because it allows them to wash their bedding without a trip to the dry cleaner.
It should be drycleaned as to not damage the comforter.
Use your washer an wash it!
We have a Kenkotherm comforter that we have machine washed at least twice with no ill effects. Dave B Central Point, OR
That all depends on the comforter. There should be a tag on the one you have (or will purchase) that lets you know if it is washable. Down Alternative comforters for the most part are washable.
A king sized comforter is no big task for any washer or dryer so long as it's alone in the machine
I think you can put any down comforter brand in the washing machine. With mine I used Woolite in the wash and then use dryer balls in the dryer. Usually I lay it out the whole day after cleaning it so it can dry thoroughly. The easiest approach is to get a nice cover for the comforter. You'll be able to wash the cover much easier than the entire comforter.
It will probably be okay to machine wash it as long as you don't use warm or hot water.
Dry cleaning a down comforter is the practical method. Attempting to wash one at home will lead to the down bunching up in corners or forming lumps elsewhere. The comforter will never thoroughly dry and will smell musty. The damp down can mildew leading to allergies.
You should wash in warm water with a sensitive detergent.