It's magically viable. I don't believe "intent is everything" but taking some of your willpower and shoving it inside a material object is the foundation of a lot of sorcery out there.
Especially when we are talking about consuming the stirred intent, feeding someone (including yourself) your enchantment is very magically powerful and can do things beyond just 'setting focus'.
You don't have to choose intents that are only related to self-enchantment ("I will have a good day today"). You can also choose intents to enchant the world around you ("I won't get stuck in traffic today").
It's a solid way to start examining your own beliefs and discovering what magic works for you ("weird, stirring intent only works for me when I use a certain folk charm...").
It's a good way to explore the problems and potential solutions of magical fatigue, or, are you the kind of witch who has enough energy to extrude this kind of magic every day? Or are you the kind of witch who must seek alternatives due to fatigue (such as permanent spell vessels)? Probably better to know this sooner rather than later.
Stirring intent into food or a beverage tends to have short term effects that last hours to a day or two and that means you can experiment with a wild and rapid amount of fun magic in a relatively short amount of time.
It's also a foundation to some more complex forms of sorcery which function on a basis of shove willpower into material object, now with extra steps correspondences. I.e., it's no use to have 50 herbs on the shelf if you don't know how to shove their magical wooblies into the candle, and stirring intent is shoving magical wooblies into things on perhaps its most basic level.
It actually works quite reasonably, decently good, if you've had some practice on it, to produce miraculous effects in your life without having to sit down and cast a spell (the trade-off I typically find being that in the short term, energy exertion might feel lower compared to prepping and casting an entire spell; but long-term, I'd bet you're allocating a lot more energy over the course of a month to stirred intent you do every day versus a single more serious spell to set the same effects for a long period of time).
You get into the habit that when there is an Actual Problem happening to you right now IRL, you can literally fix it right now IRL, instead of having to wait for a special moon phase or to plan an entire spell.
You develop the skill of casually enchanting shit, which is kind of a big deal for many common types of sorcery. E.g., making the incense do something special, or making the jar do something special, all often comes down to a form of stir your intent into it, and a spell with 15 vague steps that feels overwhelming can suddenly become, "ah, the spell instructs to burn a Cleansing Incense; I can do that, because I have incense, and I know how to stir Cleansing into it."
Having a lot of casually enchanted shit around you IRL in your day-to-day can really help develop energy discerning skills as now there are lots of various things around you that have been worked over magically and may change on a day-to-day basis, giving you the basis for a lot of intuitive energy reading practice.