Getting back to the original post.
So you are Autorotating from 1000agl in your R22 after the engine/drive belts/clutch shaft fails. Which hand do you use to activate the ELT/PLB? The one that is preserving your life by holding the collective lever down? or The one that is preserving your life by guiding you to a place of landing and ensuring you have adequate airspeed to pull off the landing? Which hand do you use to change radio frequencies for that matter?
The truth is, if you are concentrating on anything other than landing the machine at the best available or only spot....you aren't going to make it!
So the answer is, you put out your Mayday call on which ever frequency you have selected at the time. Once safely on the ground....worry about the rest.
If in a fixed wing and you have a little more time it makes sense to use 121.5. You may not be in radio range of anyone on local LOW area frequency and any jet traffic will be on a HIGH area frequency.
Forget about groping around trying to find/turn on your ELT/PLB... what bloody nonsense! From 1000' you should be concentrating only on flying the aircraft.
Furthermore... It is almost a guarantee that jet traffic somewhere will hear you on 121.5, unless of course there is a bloody ELT squawking its head off.