Yes, I sure understand how you feel. IMO keeping the plant upside down is the best way until you're ready to repot in the spring. Now, here's something that may help you further...
I got a lovely little Mammillaria perezdelarosae from Miles' To Go in December 2013. Not so little anymore as it kept growing and growing -- here it is in September 2021:
Not etiolated, but elongated a lot more than is normal for the species. The lines show you where I plan on cutting off the head for rooting and cutting off the elongated part so that I have the base and its root system there for growing offsets. Thanks to our professional horticulturalist-in-residence, this gave me an idea on how to approach the rooting process:
I'll modify Mike's approach a little bit -- instead of using a styrofoam cutting box (which I don't have anyway) and dry sand with a touch of humus (which I don't have either), I'll use a glazed ceramic pot and a fine 60/40 pumice and granite gravel mix ("fine" means a grain size of 1 mm.-3 mm., which is finer than the mix I generally use for my cacti). Unfortunately circumstances prevented me from doing the chop-chop, but I will be able to do it early next spring. Once I put the perezdelarosae's head into my version of Mike's cutting box, would I be patient enough to follow the rest of his advice? Can't argue with his expertise, so the answer is yes. And I believe that what Mike and I are suggesting here should work well for you too.MikeInOz wrote: ↑Sat Sep 11, 2021 3:25 am I do use sulphur to dust large cuts. The trick is to properly season the cut. I normally sit the plant upside down in an airy shed until the wound is quite hard and the plant body dehydrated a bit then sit in a styrofoam cutting box on dry sand with a touch of humus in a warm slightly shaded spot. Lightly misting now and then seems to stimulate rooting, then when the roots have broken, a good soak followed by complete drying and repeat the cycle. I find it's good to let the plant root in the box for a whole season before lifting.
By the way, why did the perezdelarosae get so elongated? At first I thought that it wasn't getting enough sun earlier in its life under my care, and this may have something to do with it. However, I think the bigger problem was 7 years of too much Nitrogen and not enough Potassium. I started correcting the imbalance by adding a small amount of Potassium sulfate to my Dyna-Gro 7-7-7 watering solution last year, upping my fertilizer game with a Cal-Mag supplement this year, so the perezdelarosae should be happier once the head roots and the base begins offsetting.