As an experienced instructor, I will not do EOLs to the ground in an R22, sure, I can do them, but it's just too easy to bend up the aircraft, get the sack, get a reputation etc. I will do them in the Schweizer with a student, because it's a much more forgiving aircraft for it.
Engine failures are EXTREMELY rare, you're much more likely to get some sort of malfunction/chip light/partial power loss, than a full-blown engine failure.
Just look at the PPL accident stats, it's -never- engine failures, it's always collision (sticking the tail into a fence etc), continued flight in crap weather (bad decision making), dynamic rollover, overpitching, VRS etc. You're much better off emphasising these things in training rather than doing autos over and over again.