I tried this in a pickup game when I was a kid, after losing my shoe trying to play defense. It didn’t work then, either.
Apparently there’s no specific rule against this — shouldn’t there be? Big East preseason rookie of the year Shayla Cooper is the (likely) culprit, who added one shoe block attempt to her 17 points in the box score. Associated Press, via DC Sports Bog:
In the Georgetown-Richmond game Friday, freshman Shayla Cooper lost her shoe early in the second half and tried to block a Spiders’ 3-pointer by throwing the sneaker at the ball. She missed and so did the officials, who didn’t call a foul on the play. Or even a “soletending” violation.
“Picking up a shoe and throwing it is not a rule in the rule book,” secretary-rules editor for NCAA women’s basketball Debbie Williamson said laughing. “It’s an unsporting act as there’s no rule for throwing equipment. It should have been an unsportsmanlike foul.”