have to consider too that pam is used on cooking pans that go in the oven that get as hot as 300-450*. Doubt the exhaust tips get quite that hot. Plus what banger said as well. I think that might be the cheapest best option
That could work to. Thats why I thought of maybe using header wrap. You could zip tie it around the pipe to hold it on and it can be reused. Even though PAM and other options could work Id still rather have the pipes covered with something, just a peace of mind thing.
How about some is that soldering heat shield cloth? I know that stuff is finerglass cloth good for direct flame up to 4000 or so degrees. Or welding heat shield cloth. 2 sheets of that won't run you mor than maybe $30