This basically is a short showcase for Hal Le Roy and sisters Cherry and June Preisser. There's a fairly basic plot about Hal working for Complex Washing Machine Company. Their sales are slumping - the sales manager believes that knowing good jokes are the key to making sales. Complex has joke writers - all who happen to think the same joke is hilarious, including an uncredited Ed Wynn who has his secretary write down a joke he heard on the radio - told by Ed Wynn.
Hal Rogers (Le Roy - they don't want to make things too confusing by giving the characters a different first name from the actors) is the one salesman who is making record sales. His gimmick? Singing a song about washing machines (not a common theme for the Billboard Top 100) and tap dancing.
The sales manager sends Hal to 80th & Park Avenue, the home of the owner of Complex Washing Machines. Before the lady of the house shows up in the foyer, there's a variety show going on. There's also this weird bit where portraits start singing. Hal also falls in love with one of the daughters of his former boss. This manages to get Hal fired, but has a great job offer waiting for him, training the sales staff for a competing washing machine manufacturer - the Come Kleen Company.
This is without a doubt, the greatest movie ever made about singing tap dancing door-to- door washing machine sales people.