In the genesis of recreational diving I was a advisor or a consultant to a number of companies.
Sea Tec /Inflatable Systems was established by a pioneer spearfisherman/diver ex Aerospace engineer Harry Rescigno (Pro- Ree cen O) in the SoCal city of Orange. At that time the European developed large vest were beginning to appear in the American diving market; the Fenzy and the equally tough Nimrod. Both were equipped with oral inflator mouth pieces which were difficult to use.
Harry went to work and designed and developed the first push button oral inflator. Soon all the major manufactures were ether copying or had developed their own version of the push button inflator.
Harry next project was to develop the original concept of the double bag unit, The outer bag was of tough protective ballistic material the inner bag was of a much more reasonable priced easy to replace plastic. Initial tests were not good - the inner plastic bag was a mother lode for breeding mold. After testing a number of suppliers one was accepted and became the standard at that time for the dive industry
Soon leakage problems developed in the inner bags from salt crystal growth due to lack of preventative care.
After considerable experimenting with the products available at that time it was determined that the common "Dawn" dish soap was the best antidote.
The recommended procedure was to depress oral inflator, then squirt a liberal amount of Dawn into jt followed by water -- (at that time from a hose) fill with about a 1/2 gallon of water and shake vigorously
Drain - repeat filling and draining until the water existing from the hose does nit have a salty or soapy taste.
Inflate the unit to about 1/2 capacity and store in a cool place
Both Sea Tec/Inflatable Systems and U S divers aka now Aqua lung did a 24 hour QC test for leakage on their inflatable units -- If it leaked it was rejected and repaired or rejected and scraped
I would suggest that all once again view Alex Peirce's BC maintenance video clip previously posted by
@Tom_Ivan .
Sam Miller,III