I don't really want to ruin the felt lining.
Ah, I didn't know that it had a lining. Most silicone cases don't.
A lot of cases stink these days. Be it the type of rubber used in bumper cases, finishing agents and dyes used in leather, or bonding materials and plastics used in rubberised/synthetic cases. Often these smells dissipate over time, but sometimes they don't and you will know instantly whether the smell your case emits is too bad to stomach.