One of my earliest "jobs" in aviation was as an unpaid (but compensated with experience and flight time) line-boy/hangar rat. I'm sure that was the first time I washed an airplane windshield, and I used whatever goop in a bottle was thrown at me by the FBO owner. In the many decades since, I have probably used just about every chemical available to clean windshields and windows, including good old H2O, and I am still looking for the magic elixir that simply makes deceased bugs and other debris leap off the canopy when it is merely brought out of the cupboard. I am still waiting - but a new product from McFarlane Aviation Products comes pretty DAM close!
McFarlane sent me a sample the other day after I told them I had four airplanes here that all had excessively buggy windshields after a summer's month worth of flying - a good, serious for any such Substance. "D A M Window Cleaner" is the brainchild of Dave A. McFarlane, who obviously has been searching for the magic elixir at least as long as I have. Although I have no idea what is in it, I can state that I have never seen anything dissolve bug guts as quickly, or as easily. I sprayed it on, and by the time I had the rag ready to wipe, off they came. A little polishing and the Carnuba wax that is part of the formula made the perspex sparkle. This is good stuff!
I did a little comparison between my other favorite bug dissolver (Bug-B-Gone, available at auto parts stores), and hands down, the D A M was quicker and cleaner. The little 1.5 Oz container cleaned four RV canopies, and still has some left in it - and is the perfect size to carry in the cockpit for cross-country flying. Now I just have to get a refill - I think I always am going to want to have this along. Their website lists the 1.5 oz size at a discount price of $2.49, and the 16 oz bottle bottle at $7.98 - not outrageous in the world of airplane supplies.