I have not been soaking my regs in either solution. I was waiting to hear from some of the regulator technicians and what they see with the internal seals/grease/lube/etc before I start doing that. I'm hoping to followup with a whole bunch of Reg Tech's that I'll meet with at DEMA in 6 weeks..
I regularly soak my regs in the same revivex/mirazyme mixture. I've personally not had any issue with my regulators. I only service my primary regulators (primary and pony) every two years. My reg tech has not noted any issue with any of my regulators after regular soaking in the stuff.
I have a process that involves two rinse tubs. I put my nasty stuff in one smaller tub (wetsuit, pocket shorts, dive bag, and boots). That is all I soak in that one. I put my less nasty stuff in another, larger tub. Initially I soak my backplate, wing, STAs, lights, fins, cutting devices, DSMBs, etc, in that tub. When those are soaking, I thoroughly rinse my regs (pressurized) and tanks with the hose. Lastly, my Sharkskin dive socks, hooded vest, and my dentex gloves are washed in woolite in the washing machine and then hung to dry. All of this I do in the first 60 minutes or so upon returning home at the end of a dive weekend.
I let everything in the tubs soak overnight. The next day I will remove all of that stuff, dump the "nasty" tub and soak my regs (pressurized) in the less-nasty, larger tub. Lastly I use that same "less nasty" tub to soak my tanks for several hours each two at a time. At the end of that next day everything is out of the tubs and drying. I've been using this similar process since moving to FL 6 years ago. It seems to be working as my gear continues to hold up well to monthly dive weekends.