The great Orson Welles used to top up his forever needy coffers with voiceovers and occasionally appearances in ads, for Domecq sherry I seem to recall.
Here’s a version by Neal Williams of a famous altercation between Welles and a pained but polite advertising type about a voiceover for Findus frozen peas; the great man is not impressed by the script (our thanks to George Parker for this one).
But if it all made sense would there be any advertising?