I Don't Know If Cleaning The Rubber Inserts With Alcohol Would Help Or Make Matters Worse. You Can Try It. Also, Try Cleaning The Glass.
I don't know the design of your wipers. Sometimes a plastic or metal retaining clip can be removed from the blade assembly after it is taken off the car. Inserting it from the opposite direction allows one to rotate the blades 180 degrees and reinstall them.
The rubber inserts "take a set" from being parked almost all the time and then they chatter. This approach might do it. They will park and take the "set" out.
I have an Auto parts store that I use that stocks all the inserts and I regularly replace them at a very reasonable cost. Most places don't have all the replacements and most people don't bother with them.
I have heard of people gently bending the wiper arms so they are more parallel to the glass, but I've never had to tweak any.