I tried out the Zestra
The only effect it seemed to have on me was to produce a warming/heat sensation in the genitals. It did not arouse me mentally, or make me feel significantly different physically, or make it easier to orgasm (somewhat hard to gauge, since the preparations for doing this put me into a state where I orgasmed fairly quickly anyway). It did not make my orgasms feel any stronger or better than usual. It did not cause insertion of a dildo* into my vagina to feel any better than usual.
(* - how quaint; LiveJournal's spell-checker doesn't recognize "dildo" as a real word. And for that matter, it doesn't recognize "LiveJournal" either.)
Despite the website saying that Zestra is not flavored and not the best-tasting choice for oral sex, it did have a good scent and did not taste bad... it is simply an unflavored oil with hardly any taste at all. It did make my tongue tingle a little bit. I put some on my lips too, but it did not produce any sensation there.
I haven't tried any other heat-sensation producing products like the ones containing capsicum, so I can't give a comparison of this to those.
I wish I knew what it feels like to experience a whole-body orgasm with the "fireworks" and contracting muscles bit. I wonder if I will ever experience that. It seems doubtful, since my body has never done that so far.
I think I'd probably gain more pleasure from having a good in-depth mental fantasy again like the ones I used to have, over any physical orgasm, no matter how strong. I wonder whether I will ever have any fantasies like those again.
It seems like I've heard that many females never experience orgasms, but I haven't heard as much about females who experience only "weak" orgasms like mine. I wonder how common or uncommon it is to only have the physical sensations which I have. And I wonder if males experience orgasms along a continuum from weak to strong too; in other words if some guys only experience weak orgasms (or none at all), while some guys only experience strong ones.