I am not sure how applicable my experiences are to what you are doing but:
Make sure you are using the minimum settings needed to cut the felt in order to minimize char. It’s worth doing a materials test.
Sand some char off the edges with fine sand paper, a sanding sponge or emery board.
Wash, if it won’t destroy the piece. Felt is more resilient to washing than people sometimes expect.
I have noticed that the smell fades quickly over time. Ventilation and, sunlight (as @evansd2 suggested) will likely accelerate the process.