IDK ... going "cold turkey" really doesn't work for me or my spouse. We always end up rebounding. I think easing into something is actually a pretty good idea. Our big achilles heel is eating out. So, when we make dinner or I bring my lunch to work, I sort of feel like Tom Hanks in Castaway when he proudly proclaims "I have made fire!!!"
And then it becomes a positive feedback loop and I think, "well, I did it yesterday and it wasn't hard, so I'll try it again today." And, since eating out is something that we really, really enjoy, it's nice to know that we have something to look forward to on those days when we "allow" ourselves to eat out.
My spouse also has a self-identified tendency to "rebel" when she feels like there are restrictions, even if they're self-imposed, so trying to be "perfect" ("the 'p' word") never works for us.
And, even if someone is spending some money on the weekends, they still have the money from the week that they didn't spend. It's not like it disappears just because the person isn't perfect.