^^^ This ^^^
But....
Marshmallow is the least sweet. If you're using it purely as a sweetener then you may find you'll end up with more of a creamy flavor than simply sweetening your original flavor.
EM is a mild sweetener. 1-2% is a good call. It's pure sweetener so it's not going to change the taste of your original flavor much, but it is mild. That works well if you're only wanting to slightly sweeten the flavor, but if you're wanting something a lot sweeter it's probably not your best option.
Sucralose is a STRONG sweetener. A little bit of this goes a long way. I've found that 1 drop per 10ml of
juice can make a strong
juice like peppermint taste like candy because it's so strong. 1 drop per 5ml and you'll probably be overwhelmed by the sweet and get very little of the other flavoring. Use sparingly in small quantities, but it's really good to use if you're either wanting a lot of sweet or mixing a large batch of
juice and don't want to have to use a half bottle of EM to make it sweet.
A lot of people also like cotton candy flavoring to use as a sweetener, but I find it to be a bit too perfumy for my taste. It has a strong scent that can mute and dominate other flavorings.
