If you want to end up in nutritional ketosis, spoonfuls of sugar are the last thing you should be putting into your mouth in whatever form! We don't need any sugar/carbs from external sources, but we do need some fats. Just keeping your overall carbohydrate consumption as low as possible for a while - 20-25g max carbs a day - should soon get you into ketosis if you are not there already.
Tthe original reason for me aiming for ketosis (as per Atkins induction phase), was doxtors orders to lose some weight, but as far as I'm concerned now the main benefit's been that my body has also converted (back) to dual fuel burning mode using both the few carbs I eat plus fats as fuel, and this provides a constant and steady source of energy, and keeps my glucose levels stable.
I've used an old style Ketonix, which acts like a breathalyser (which I believe some people actually use too) to measures acetone levels in my breath. This has a colour coded/traffic lights system to indcate ketone levels: none, low, medium and highish levels of nutritional ketosis. I never found any infornation on how these colours might relate to actual numbers though! It's not as accurate as a blood ketone test, but it served my purpose, and over four years has been far cheaper than having to buy the very expensive test strips for a meter. However the reader that came as part of my first Libre sensor kit can act as both a glucose and ketone tester as well as being a sensor scanner, and I've used a few strips when I've been feeling rich. It's also possible sometimes to taste or smell the acetone, and I get a taste occasionally, and I believe some people can smell any waste ketones in their wee, I may see anything from none to high readings on consecutive days with the Ketonix and I've since learned that you don't need to be in ketosis once your body has re-adapted tofat burning, as it switches in and out depending on what fuel is available to use at the time. Whch seems to suggest that actual levels may not be all that important and there's no real need to aim for high levels - unless for a specific reason. And once you've started burning fats, there's apparently no need to keep to a very low carb level, - under 50g a day should be fine, but preesumably depends on the individual.
Robbity