Mozingo's Synthesis is similar to Clemmension's Reduction or Wolff-Kishner's Reduction. It is used to convert aldehydes or ketones to methylene groups and the reagents are SH-CH2-CH2-SH and dry, gaseous HCl  in the first step followed by hydrogen gas, Nickel and high temperature and pressure in the second step. The intermediate is a hemi-acetal.

yes you get a 1,4 dithiane in the first step (which is a thio acetal/ketal) and after that it gets reduced by H2/catalyst to give the alkane. The advantage in this method is that it can be used in both base and acid sensitive compounds unlike the other two methods afforementioned!

Mozingo method is used to convert carbonyl compound into its dithio-acetal or ketal using ethanedithiol in the presence of a Lewis acid.. This obtained dithio-acetal is hydrogenlysed over Raney-Ni. 

suppose that  is the carbonyl comp. to be treated ,, then ,,let it react with ethane dithiol first that is ::

in presence of lewis acid(mostly   )  at room temperature,, to form dithio-acetal accompanied by the release of water molecule 

R     S---CH₂

   \  /          |

   C           |

  /  \           |

R     S---CH₂

the above given type of compound will be formed,, which when hydrogenlysed with raney nickel,, is reduced by breaking the bonds of the ring,, i.e, S--C bonds and Hydrogen is attached there,, thereby giving back ethane dithiol and giving ...

The first step is simple nucleophilic addition across C=O in presence of acid to form cyclic thioketal.

The second step is desulphurisation which involves the breaking of a C-S bond in an organic compound, and the source of hydrogen is usually the hydrogen adsorbed by the Raney NI prepared in the usual way. The first step is believed to be chemisorption of the sulphur atom on the surface of the catalyst, and this is then followed by fission of the C-S bond to give free radicals and finally hydrogenation ( exactly similar to hydrogenation of alkene).

The overall mechanism thus you can make in two steps usuing mechanism for acid catalysed nucleophilic addition across C=O and catalytic hydrogenation of alkene with Raney Ni & H2.