A Few Tips...
Regarding washing the towels: Use any laundry detergent sparingly with hot or warm water. Or, try Simple Green... sparingly. Too much detergent... and not enough rinse... will leave a dry residue in the towels. Once the residue is wet again, it will smear. Towels MUST be rinsed thoroughly.
One way to see if the laundry equipment is the culprit, take a few loads to a laundromat or even home for laundering. It could be that you have contaminated your washing machine with chemical residues that transfer onto the toweling. All it takes is a load of greasy towels with tire or vinyl dressing, especially if you use only cold water. If you only have one washer, consider a second one (nothing fancy) dedicated to window towels. And use hot or at least warm water for washing.
Window Cleaner: There are many great commercial glass cleaners available from janitorial supply outlets, including Windex. But why not make your own? A few capfuls of JOY (original yellow, not ultra ) dishwashing detergent or Simple Green in a 5-gallon jug. As an option, also add a few ounces of ammonia for shine. In cold weather, add isopropyl alcohol to aid in drying.
Segregate your window towels from every other towel, and treat them carefully. If you use cotton terry, do not wash them with microfiber. Each should be laundered separately... with NO bleach.
If the cotton towels have lint, add a cup of vinegar to the wash.
Hope that helps...