Not all MF towels are made the same.. however with that being said, I personally don't think it's worth it to spend big bucks on simple towels. Sams has a good deal on them for like a 25 back for $10 bucks. My buddy throws his really dirty ones away and just buys a new bag. To wash them, use regular detergent with a splash of vinegar (optional). Just don't use any types of fabric softeners.
A cleaner wax just contains some extra properties that help remove some stubborn stuff that regular washing cannot get. That's why your applicator will turn brown after a while. It's not wax. That's dirt. It may contain some polishing properties depending on the brand but that's another topic.
However, a clay bar will remove everything when used properly. That would remove most of the need for a cleaner wax, even though that is the most common OTC wax. Using one after claying won't hurt. Just a little more work and more dust for you. You can youtube videos on how to do this if you never have.
If you want a best I can get at the minimal, this is what I would recommend. Buy a clay bar. Cut the clay bar in half. Safe the other half. Clay the car. I don't like telling everyone to buy a specific product, but I don't know too many alternatives. It's called Klasse All In One. It's a German imported acrylic sealant. It's very popular in the detailing world (see autopia.org). It's about $20 bucks for a bottle. It's very easy to apply use very little product to cover a vehicle. It lasts about 3-6 months on the car. It also contains light polishing properties which is good for what we're using this for. You can also consider this the first "layer of wax." However, you cannot layer this product. What you'll want to do is put another coat of wax over top of this. Find one without all that cleaning stuff in it. Personally I use P21S. Pure carnuba wax. Goes on like butter. Comes off like, well it's easy. And little to no dust!! but again, More than most people want to spend. So do some research! P21S would never touch my car without the prep work though. It would be a waste of product IMO.
This is what I typically recommend to people that are below the car enthusiast level, but obviously steps above the average car owner that love their car, but don't want to spend a fortune on taking care of it.
People that don't want that extra hassle or cost. Just use a popular OTC wax. You'll be fine. Every 6 months or so clay bar it and use the same wax, you will still be happy with the results. The above is for people looking for more.
"We live for a good time, not a long time."
RIP Colin McRae