Scott
Sodium metabisulphite is a general purpose reagent that performs many functions in industry. one of its' applications is the sterilisation of wine and beer brewing vessels. It certainly would stop fermentation by killing yeast.
In our industry it is used as a reducing agent, which is especially effective against a range of tannin/cellulostic discolouration staining. Though it can be used in its' 'raw' state, I am loathe to advocate its' use to an unknown audience, preferring to recommend the use of a branded formulation, with care and in accordance with manufacturers' instructions.
Some cautionary notes:
The fumes emitted can cause bronchial irritation, but when mixed with an acid, the fumes are toxic.
Its' action is boosted by heat and care has to be taken in regard to the amount of heat used - I have seen wool fibre turned to jelly by sufficient heat applied to produce sulphuric acid.]
It will also reduce other dyes. When using any product containing this reagent, especially when using with heat (eg thermal transfer), its' effects should be constantly monitored for the loss of native dyes. As I have said before, experience in its' use should be gained on practise pieces before application in the field.
Prochem B175 did contain this substance until its' reformulation a few years ago and I believe I am correct in saying that it does not feature in any of their product range.