I have the condensate from my home air conditioner (central air for 2100 sq. ft. house) running into a sewer line through an S-trap. This has worked well for years. i would rather not have the condensate pumped to an outdoors drain. The AC unit has year-round use. There is no risk for me of the trap running dry. Occasionally however with this set up the S-trap starts weeping from its own condensation on the outside of the trap and pipe, due to the coolness of the AC condensate trapped inside. This is drawing water bugs. Can I spray insulation on the trap to minimize or prevent this? I live in southern California. I'm sorry I don't have a picture handy. Thanks.

I've always used a brush instead of crocus cloth. Any reason i should try the grit instead? Does the cloth leave a smoother or cleaner surface for soldering or compression ferrules?