We’ve used a simple PVC pipe frame attached on a slight slope over the schach roof and used a rolled up tarp on a second piece of pipe attached to the “high” end of the frame so the tarp can easily be rolled up and pulled out. The entire frame and large tarp can be purchased at any Home Depot or Lowes for minimal cost. Two concerns. First, its good for light rain but don’t use it when heavy downpour is forecast since the water can “pool” and the weight will collapse your succah. Second, getting up on the ladder to roll it up or down at night and after a few glasses of wine can be a challenge
Also, I’m sure there is some chumrah somewhere that says our entire “stay dry” strategy is apikorsus and succahs are supposed to get wet.
