Douglas Harper's Etymology Dictionary
toot sweet
"right away, promptly," 1917, American English, representing U.S. soldiers' mangled adaptation of French tout de suite.
Wiktionary
toot sweet
adv. (context slang English) Real quick, in a hurry.
Usage examples of "toot sweet".
I know he's never been there, but he'll find it in his star charts, and he'll get us there toot sweet.