Frank wanted to ban ALL practice autos in the R22 but the FAA would not let him
Yes, they are tricky to auto-rotate well, but as long as you stick to some simple rules, you should be ok
How about...
1 - at least 15 knots of wind. no gusting/shear
2 - always do them dead into wind
3 - never more than 10 gallons of fuel on board
4 - never roll the throttle completely off, roll it to just under 80%
4 - FULLY brief the student beforehand how it's going to work. if it's the first few times a student has done an auto, get them to follow YOU through very gently.
5 - do not do them to the ground
6 - do a check at 300 feet: airspeed at least 60 knots, RRPM in green, into wind, no excessive rate of descent. if not... roll on power and go around.
7 - as soon as you start the flare, roll on throttle and rejoin the needles
8 - if you're unexperienced in teaching autos, flare a bit earlier, bring power in a bit earlier
9 - never do more than three practice autos in any one flight
10 - try to do a long progressive flare, as oppose to a late agressive one. gives you much more time to see if its going ok