To a certain extent, yes, celebrities had some obligation or commitment to personally owning and using the appliances or other goods that they publicly endorsed.
This was often the case in the past with television celebrities when a program that the celebrity appeared in was sponsored by a particular company or organization whose name was part of the program's title.
There are two examples that readily come to mind. The first is the General Electric Theater which was hosted by Ronald Reagan on CBS from 1954 until 1962, according to the Internet Movie Database (IMDb). As part of his compensation for appearing on the show, GE furnished his and Mrs. Reagan's home with pretty much everything in their home furnishings line. In addition to his television duties, the future president made personal appearances for the company at trade shows, conferences, and factory locations.
The other example is Bob Hope, who was a similar spokesman for Chrysler automobiles. In this case the program was Bob Hope Presents the Chrysler Theater which, according to the IMDb, appeared on NBC between 1963 to 1967. Also, if you watch his movies made during this period, you will see that Chrysler automobiles are prominent in these productions.