The Oxford World's Classics edition of Persuasion that I'm reading has this to say:

Gowland: a lotion whose use would eliminate all varieties of skin disorders, or so its manufacturers promised in the many advertisements that they issued in prose and verse. Gowland's manufacturers advertised in the Bath Chronicle, the journal a Bath resident like Sir Walter would read...

Advertisements in verse? Oh yes, please let there be advertisements in verse!

Unfortunately, all I could readily find was this quote from 'For the ladies.' John Strachan looks at women and advertising in late Georgian England. (via the Google cache):

Such rhetoric excludes the gentleman consumer, of course, and sometimes cosmetic advertisers selling a product which might be used by both sexes addressed men and women separately, marketing the same product differently. For example, John Gowland's spot cream, Gowland's Lotion for 'cutaneous eruptions', a mid-eighteenth century product that was still popular in the early nineteenth century, was advertised in the Sussex Weekly Advertiser in February 1791:

TO THE GENTLEMEN THIS LOTION is an EFFECTUAL, REMEDY for all SCORBUTIC and HERPETIC eruptions of the FACE and SKIN, from the most trivial to the most DISFIGURING and INVETERATE; from the smallest PIMPLE or TETTER to the most universally SPREADING Eruptions or Ulcerations. For redness of the NOSE, ARMS, or other part, and in short for every train and species of EVIL to which the Skin is liable, whether VIVID and...