Trapdoor Rifles

I have a couple of guns which lived in a smoker's home for many years, and have a layer of tobacco smoke residue clinging to the wood and metal parts.
One is a mediocre trapdoor, but with usage history, the other is a newer gun, and pretty pricey.

Any suggestions on how to remove that?
I am especially concerned about any process that might include caustic or acid stuff that will harm the blue finish on the metal.

Has anyone had any experience with this problem, and what worked, or did NOT work?
Thanks.

I've not had a problem with tobacco smoke on any of my firearms. I did have a carbine with some kind of goo on it, the only way I can explain the substance.
I used G96 on it and it worked rather well.
Just spray it on and let it soak a while then just wipe it off with a clean rag.
It's also safe for blueing and other metal parts.
Al suggested that I use it some years ago.

Hoppe's 9 bore cleaner on a soft rag worked for me on a rifle that hung over a fireplace in a smokers home for many years. Go slow and turn the cloth frequently.