I discovered the benefits of microfiber a year or so ago. Sounds like the cloths you found are treated with something, what happens when they get dirty and you wash them?

I have tried lots of different techniques for removing bugs after each flight over the five aircraft I've owned now and believe my current system is the best so far. After each flight, at least where there are bug accumulations, I take a standard 16x16 microfiber cloth, saturate it with water from a 5 gallon jug I keep in the hangar, and wipe down the leading edges, gear legs, wheel pants, and prop. I've tried every type of "quick wax" or "detailer" on the market with standard terry towels and the water/microfiber removes the bugs the fastest, go figure.
Then when I want to get the light dust off everything else I'll use a larger microfiber towel with Turtlewax Express Shine. This works great on the plexi too. Anyway, that's my system and it's the best combination of materials and techniques I've tried so far.