Complex sentence: In this role, he proved vital in advertising and sales promotion for the company, and in particular is credited with the idea of adding the label "20 Mule Team Borax" to the company's product, which subsequently became a household name throughout the country.
Split into simpler sentences: In this role, he proved vital in advertising and sales promotion for the company. In particular he is credited with the idea of adding the label "20 Mule Team Borax" to the company's product; this subsequently became a household name throughout the country.