His smoking IS something that you have the right to ask him to change. The senses play a HUGE role in sex, especially the sense of smell. People that smoke do have a smell to them. Showers don't take it away. So ASK him to quit to help YOU in your quest for better sex.
As for turning down sex, you can do this, but it is better if you make an appointment for it at a better time, and then KEEP that appointment. My guess is that your husband will accomodate, as long as the appointments are kept.
