'Clobbering' is usually understood as when polychrome 'enhancement' is applied over an existing and complete underglaze blue motif and, a not intended part of the original design, usually to make an item more saleable. This term is today used on all Chinese porcelain to which an enamel decoration has been added in Europe. The original meaning was however when enamels was added as a repair to hide a defect, and should be distinguished from Amsterdam Bont, German Hausmalerei, (German: "home painting"). English Gilding and I think, China Burners repairs.
A western traditionally derogative name referring to Chinese export porcelain that has got its original underglaze blue and white decoration added onto in Europe with a later colored enamel decoration. The secondary decoration were sometimes limited to only a new or additional borders, sometimes rough foliage, figures, animals, birds or full landscapes or sceneries, sometimes adding to the old decoration, sometimes randomly filling all available space and sometimes just disregarding the old underglaze blue and white decoration as if it wasn't there.
Pieces with the least merits seem to have been produced in London during the second quarter of the nineteenth century when apparently a great deal of indifferent and unsellable Chinese blue and white 18th century left over stock were embellished with anything that was colorful.
The practice seems to have originated in Holland but spread over Europe with the availability of items to decorate. This kind of work was extensively done both in Holland and in England during the 18th and early 19th century. The English establishments that offered this service were known as China burners and the enameling was referred to as that the colors was "burnt in and impossible to remove". Some of these "China burners" also seemed to have offered porcelain repairs where broken pieces was ceramically mended in a re-glazing process.
Another praxis that needs to be considered in this, was a related process where damaged or second rate porcelain was improved or mended by hiding the flaws under newly added decorative elements such as random enameled flowers or insects. This could indeed be a literally correct use of the word clobbering as compared to what was done to broken shoes.
By the end of the 19th century clobber was found in the English language (Oxford English Dictionary) together with clabber, while referring to "a paste used by the shoemakers to patch holes", which is not an unlikely origin
The word "Clobbered" could based on this, be understood as patched up or repaired.