I have a central AC unit with a 3/4" PVC condensation line that runs to the outside. I usually pour some bleach down every 30 days or so from the cap on the left side. But that only cleans the vertical pipe and downstream. Last month the line was clogged on the short horizontal pipe, slim buildup in that pipe that required me to take the tee and 90 elbow apart. I was wondering, is there a better way to clean that horizontal pipe? Should I cut that pipe and insert and TEE and pour bleach down that horizontal pipe instead? What if I go to the right and remove the float switch and pour bleach down that elbow, will that run to the left side pipe or is that a bad idea?

Looking to improve where the large and small lines, and electric wire, enter the house. Rubber pipe insulation needs replacing and the caulking at the exterior wall opening is dried out and ugly. First wondering if there's a way to help protect the lines from corrosion; they are not leaking but have been in the elements for 20 years. Before replacing the rubber on the larger line, and for the small uncovered line, would it be wise to coat it with a spray corrosion inhibitor or rust-preventative like spray lithium grease? 2d: the caulking looks like it should be dug out and the entry opening re-done. Particularly to get a good water-tight fit for the end of new rubber pipe insulation. Wondering what to use there. The current caulk is a doughy material that has discolored and cracked but at least it is still workable. Both copper lines, the single wire, and the wire bundle all go through this hole and it is pretty big. Silicone caulking would be hard to use here and likely to end up looking bad, but a doughy material would be moldable. What about Gardner Bender Duct Sealing Compound Plug? Temps here do go below its rated temp of -20F. What kinds of materials would be least corrosive to the copper?