It is possible, but I have to tell you in eight years here, I have seen that strategy fail more than not. A little often led to a lot and either it was abandoned or No S was abandoned. Now more succeeders will come out of the woodwork, but I am reporting my observation. I don't have stats, and am not going to comb through.
If any strategy leads you to take in less than your body needs- and that calorie need can be driven by multiple influences-, you will lose. As said, there is no way to know what the sweet portion should be without knowing what the rest of your day is like. You can't eat the same size meals plus a sweet and get the same results as without the sweet. (That's true for booze, too, and even more so because it is even less satiating than solid food.) Something's gotta give! But going without may not be sustainable for you, even if it does result in weight loss. What else on your plates will you eat less of? What will bring you enough pleasure and vitality?
It is certainly theoretically possible to eat little enough even with sweets to lose weight. It's just that for some, as I say, most people I've seen here, a little is not enough. It is so easy to overdo it. I myself find it more annoying to have just a couple of bites. I always want more later. So I go for what helps me feel satisfied with what I DO eat.
I hope you would not have to become dependent on calorie counting, though for those who seem stuck, it can help them see which foods they are eating too large of portions of, if their fullness isn't guiding them enough. Then they can set guidelines for the serving size on your plate. That''s how it's worked out for me, though it's not the way I planned it. I was already in the habit of eating rather balanced meals. It was overdoing sweets especially and every day that was my big problem.
And it can be shocking how little is needed to sustain weight, especially for shorter, older women who have lost weight. For example, with my stats, I would have to AVERAGE a little over 1200 calories a day to lose a pound a week, if i had never lost weight. And that's with NO extras on S days. If I was willing to go more slowly, but I wanted sumptuous S days, N days would need to be quite spare. Having lost weight, I'd need even less. No S can't defy the laws of physics.
A 250-calorie sweet a day for me would account for more than entire day's food if I was trying to lose.
You asked.