[markeb01]

That's not something I've ever heard of, and I wouldn't recommend it. Condensation in a muffler on start up is normal, as the moisture in the outside air is drawn into the pipe and "rains" inside. The best method for long muffler life is driving the vehicle long enough to dry them out every time the engine is started. On a daily driver with a short commute this may be impractical.

This is why Sears, Montgomery Wards, and Penney's dropped dual exhaust applications decades ago. Single exhaust systems warm up faster and dry out the mufflers more quickly than duals. So they greatly reduced their warranty replacements by eliminating dual mufflers that rusted out faster.

Drill a hole of any size in the muffler will make it sound worse (like a muffler leak) and will also introduce carbon monoxide into the cabin depending on where the muffler is located.