If you use RTV silicone on exhaust, especially ahead of the O2 sensor you might be wary of O2 sensor function. Racing motorcycles I had RTV damage the O2 sensor.

https://www.amazon.com/Permatex-8142...000AANXHC?th=1

https://community.cartalk.com/t/how-...-sensors/70388

Silicone with the acrid smell is not safe.
jim