O2 cleaning a reg is not rocket science, but should not be attempted without proper training and supervision.
For that reason this description is not a detailed set of instructions.
I am leaving out details so don't attempt it without supervision of a trained O2 cleaning tech.
Yes you definitely need to be qualified to service the reg to O2 clean it.
A complete tear down and removeal of all nitrile (buna) o-rings is required.
The materials used in the cleaning must leave no hydrocarbon residue.
All other parts must be thoroughly cleaned and degreased with an appropriate agent, rinsed and mechanically scrubbed/brushed with appropriate clenaing agent and re-rinsed. Parts must be air dried kept in a lint free area until reassembled. (any lint or contamination, grease, etc is fuel that can burn in pressureized 100% O2 ). Nitrile o-rings are replaced with viton (fluoroelastomer) orings, which have a much high temperature rating (200°C) before they burn. Orings must be lubricated with an O2 compatible lubricant. The reg is reassembled and intermedate pressure set.
Care must be taken not to use this reg on other than hyper clean air or O2.
Allowable hydrocarbons of regular scuba air can contaminate the regulator first stage and become the source of ignition.
Many argue that diaphram regulators should not be used for O2 service, because of the lack of replacement for the diaphram.
For this reason piston regulators which are relatively easy to service and have fewer nitrile components to replace are the prefered choice.
100% O2 is not used deeper than 20 feet on deco, so a high performace reg is not nessessary.
Mike D
O2 cleaning & Gas Blender Tech
NAUI instr 4780 (retired)
PADI instr 202288 (retired)