The phrase "at once clean" is correct and usable in written English.
It can be used to describe something that is immediately or simultaneously clean, often in a context where cleanliness is being emphasized.
Example: "The room was at once clean and inviting, making it a perfect space for relaxation."
Alternatives: "immediately clean" or "instantly clean".
As president, Barack Obama, by working with conservatives as well as the members of his own party, can at once clean the air, create jobs and improve the national security of the United States — a triple play for the next American century.
Good ingredients for adding flavor to beans include garlic, red pepper, cumin, coriander, and lemongrass.[9] Don't use all of these at once! Clean and heat your Mason jars.
That collection, shown last February, has become one of the most popular and widely written about – not to mention most conspicuously worn by the cognoscenti – of the season, embracing at once a clean but opulent sculpturalism in its strict and silken silhouette, as well as a classic and womanly look by way of 1940s pencil skirts and 1880s decadent bird and leaf prints.
Just as Marie Kondo suggests that you clean out your closet by choosing what items to keep and what to toss in one fell swoop, all at once, I cleaned up my relationships around food and exercise.
Her other brother, Sissi, was a boy who confused their mother ("You take off that nightie at once, mister, and clean your football boots") before being transformed into: a) a transsexual, and b) "the George Soros of dodgy Internet business".
The perfumer, who prefers spicier juices in his own creations, said it was a challenge for him to incarnate Ms. Dunne's paradoxical vision: a scent at once intense and demure, clean yet floral.
Others will periodically remove all the strings at once so they can clean the fretboard more easily.
Removing all the strings at once permits you to clean and wipe the fingerboard without lifting up the strings or having to work around them.
If you have too many clothes to wash at once, consider keeping a second clean bucket nearby to store clean, wet clothes while you finish washing the rest of the load.
It shares the dry soil and hot sun with better-known herbs -- thyme, rosemary, sage, tarragon and oregano -- but lavender is the star, prized for its bouquet, a clean aroma at once floral and woodsy.
