On the razzle

• The OED suggests that "on the razzle" is a shortening of "on the razzle-dazzle", which is found at least as early as the 1890s: "I live ever so quietly; I don't drink; I don't bet much; and I never go regularly on the razzle-dazzle as you did when you were my age."
• Another suggestion is that it came about during World War I, when ships were often painted in bright zigzag patterns to confuse German U-boats. Sailors often came back on the supply ships from North America after consuming a large quantity of alcohol, and were said to have been "on the razzle". This derivation seems unlikely given the much earlier use of the phrase "on the razzle-dazzle".
• Another theory is that there was a gin parlour notorious for the extreme merriment of its customers in London during the 1750s. Its proprietor, who called himself "Dash Razzall," was an unscrupulous man of Italian descent. It is unclear as to how his name mutated into razzle, but his gin parlour was renowned for the amount of alcohol consumed, and that after he went bankrupt his family moved to Sussex, where they became renowned as being prone to overindulge.