I was taught by a DPE at one stage, and what he said regarding them made a fair bit of sense, as opposed to "always do them".
If we were gonna be doing slow stuff, like MCA, Stalling etc and weren't going to be very maneuverable... do some clearing turns first. Right/Left 90, followed by Left/Right 90.
If you're doing steep turns, you'll be at or around cruise speed, the ailerons will be nice and effective, and if you need to take avoiding action, the aircraft will respond better, so you can go straight into them without doing a "turn before you turn" as previously mentioned. Just have a good lookout, as you should be doing anyway, being a good trainee flight instructor and all.
Then, if you've done the steep turns as the first maneuver and he wants you to do something else, like a stall demo, or a chandelle or whatever... you already cleared the area when you did your steep turns, so as long as it's not minutes later and you're not miles away, you just get on with whatever the next demo is.
Made sense to me.
As an interesting side note, I didn't hear HASELL/HELL mentioned once out in the States... But we had our own practice area over barren desert/mountains in Class G, and generally did clearing turns prior to acro stuff, checked the T's & P's, set the Prop/Mixture etc, and it was drummed into us to start all maneuvers above 3500'AGL. We also didn't have flaps/gear to worry about, so that pretty much covers HASELL/HELL anyway.
Most of the guys pissed themselves laughing as I tried explaining BUMPFITCH to them too... "How in hell will the brake have been set..?", "The Undercarriage is fixed asshole" etc etc
As far as I know, in the 25 year history of that flight school, nobody has landed with the parking brake set, despite never been taught to check it downwind, or landed wheels up in anything with fixed gear.
