I would think the chewing tobacco wouldn't be too hard a problem to bin, because you're consuming it in set periods of the day, not throughout it seems unlike food and also I would expect it to have limited sales outlets unlike food, so if you pitched the remaining stuff out, you'd be able to avoid it by and large, if you had to go to specific place to get it and then stopped doing so.
The other option is if you buy it at a food outlet, use cash to buy food and take the cost of the C T, out of the budgeted finance you take with you to the store. You could tally up a recent receipt for food minus C T cost, then allow a small amount of extra money, like say $5 more in lieu of fluctuating prices week in week out.
You keep the money you would have spent on CT in a jar, then you can spend it once every 1-3 months say and buy personal effects like CD's, or clothes, or presents for other people with it.
You then effectively incentivise the process of canning the C T, to make it seem a more desirable thing to do

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