Honestly, I can't even tell. I used it religiously from about May 2010 until May 2013. I went from SL to MBL. But I was also using Ayurveda, GHEing regularly and braided up 99% of the time. Also, that's pretty standard growth for three years, esp when Njoy did that from Feb to Nov in ONE YEAR! So, I guess, no I didn't get those results.
2018 to 2020, I hopped back on the HHJ and repeated everything I did, minus the sulfur, my hair retained and grew even better without it.
However, in 2022, after cutting out locs, my hair was the shortest it has been since 2010. So last year I was really trying to see what would be a growth booster for me and since my hair was short, there was less risk in experimenting. But I could only hang with the sulfur for about a month before I had to give it up.
For me, in my HHJ, I'm very much stick-with-what-works and I avoid bandwagons. But even I was impressed with her growth that year, bc it was much more than just retention going on there. And now that you've mentioned it, I'm not sure I've seen other ladies repeat the growth that she got using sulfur.
HOWEVER, I have another theory about that and I believe she got that boost bc she wet bunned everyday, all year (and, of course, manifesting)! I've seen ladies get length quickly via wet bunning from the moment I first found the hair boards in 2009. The extra moisture and physically protecting the ends is a good combo. In fact, from my unscientific observations over the years, I'd say I've seen weaves, wigs and wet bunning give the most dramatic hair growth results on both hair boards I've been on. Also, my personal experience has been that braids/cornrows, which are usually used with wigs and weaves, provide me with the best retention. I still haven't found my secret growth booster though.