Quote From Today... Walk, Don't Run (1966)

"I wouldn't know what to do in the 
bathroom all day!"

With Jim Hutton.

Walk, Don't Run was Cary Grant's 72nd, and last, full length feature film. 

Christine Easton: After 7:45, you can have the bathroom all day if you'd like.

Sir William Rutland: I wouldn't know what to do in the bathroom all day!