A procedural swoosh spine is attached at the advance edge of the word, measured from the font's own metrics so it lands exactly where the type ends at any size. Curl, Height, Wave, Slope and Ratio shape the spine, Length sets how far it runs, and the Tail tip picks the ending. The swoosh is emitted as an extra glyph, so 3D, strokes and the rest treat it as part of the word. The SwishFx panel adds swoosh fonts and per-font defaults.
Swish is applied as an Illustrator live effect, so the text stays editable. Change the word, the font, or any slider afterwards, and save the result as a Graphic Style to reuse it.
How to add a swoosh to text in Illustrator → walks through the manual Illustrator steps, then shows the one-click version.