During the servicing of regulators, the hose ends are typically submerged into a solution used for cleaning metal regulator parts. This is an effective way to remove corrosion from hose fittings, but at the same time it may be damaging the inner lining of the hose. The interior of hoses should never be exposed to any type of cleaning solution. The damage that can occur is the reduction of pressure holding strength, the break-down of the inner lining resulting in the potential reduced flow of gas and premature failure of the hose. Best practice is the ends be sealed during servicing to insure that the inner lining is protected from cleaning solutions. Do not attempt to flush the inside of the hose with any form of solvent or other chemical, new SCUBA hoses are factory clean and if you have any reason to think they are no longer clean then the hose should be replaced.
Keep in mind that all SCUBA hoses will fail sooner or later either due to age, storage conditions or handling. Scuba hoses, regardless of brand and materials, require some minimal care. Do not allow hoses to receive prolonged exposure sunlight, as the heat and UV from strong sunlight will significantly shorten the life of the hose. Prior to every dive trip you should always pressurize and inspect your hoses for mechanical damage, corroded fittings, bulges and leaks. Dive Gear Express suggests replacing all SCUBA hoses every five years or 500 dives, whichever comes first.