Some people claim it also cuts down on nicotine. I've only ever used a diffuser back when I smoked washed tobaccos mainly so I can't attest to that. But as mentioned it will make everything significantly quieter which is nice if you watch movies or listen to music. I prefer not to use them because I like the sound of the pipe and also am not bothered by nicotine in the least.
36" Al Falkher Solid - 36" KM Copper Heart Two Hose - 22" Temsah Mini-Wheat(a.k.a. Golden Nugget)