If this is considered a symbol (reminder) of your friendship and it's not yet gone, you can also pack up the ashtray and store it away out of site (like in an attic). When you reach the point where smoking is disgusting to you, depending on the size, you can use it for something else - maybe fill it will wrapped mints. It will then not only serve as a reminder of your friendship, it will also remind you of your victory over cigarettes.

If it's already gone, ask Michelle to go on another cruise and bring you back a bowl to go along with your straw.

I'm sure she'll understand why you needed to get rid of the ashtray.