Well, to review the salient points of my previous post, a lot of "feminine hygiene" products are
marketed, but that does not mean that any are
beneficial, any more than tobacco is. The one you cite is primarily a
detergent and that is
very bad for the foreskin - or the vulva.
Another highly undesirable component - because of the risk of sensitisation - is the perfume, yet of course, this is what "sells" the product - it
smells good, which conveys the message that it is "nice" to use (whether or not it is helpful or in fact harmful).
It is convention to list ingredients in descending order of their quantity. Lactic acid, which
is a legitimate component of vaginal preparations, appears
eighth on the list you gave (ignoring the first, "aqua" which of course means
water 
).
The
problem with washing with "with special soap" (even if it has "natural pH") is that it is -
soap! And the problem with that is -
why would you ever want to use soap on your penis? Are you a motor mechanic who gets
so grubby that oil and dirt penetrate through your overalls and underwear? Whatever makes you think - then or now - that you penis and especially the area which is specially
protected under the foreskin - is in some way
dirty? How in fact would it
get dirty? Does it not stand to reason that (if you cannot retract) it is regularly flushed out every time you pee? Or do you somehow imagine your urine is "dirty"?
It is almost certain that your problem in the very first place, was allowing soap to get inside your foreskin where (except when you pee) it cannot be properly flushed out. "Smegma" - the accumulation of the surface layers of skin which is continually growing and wearing away except where it is always covered - is produced in excess when the skin is irritated and responds by growing faster in order to protectively thicken and provide more of a barrier to the irritant, so the more soap you apply, the more smegma you produce. This process is referred to as either "irritant dermatitis" or "seborrhoeic dermatitis" depending on whether the irritant is identified or cryptic.
OK,
any amount of recurrent itch is abnormal. I
think (but am not totally sure) that your itch is simply part of the irritant process and will settle if you can avoid the irritant. It
may indicate the presence of "thrush" which is often an opportunistic infection secondary to dermatitis.
Now as to stretching. Skin clearly
is susceptible to stretching. Stretching the foreskin opening is comparatively easy and straightforward. Stretching the frænulum is somewhat more difficult; stretching the remnant foreskin following circumcision to "re-create" a complete foreskin is again a greater challenge, but people succeed. So, what about stretching the penis itself? Well, there is little
evidence to indicate that this is do-able; when you read something on the Internet, you do have to consider whether it is credible as clearly, a lot that you read even where it is well-written or emotive, is simply mendacious.
You do have to always consider what is being "sold" to you, what motivation may be behind the claims. On the site you cite(!), I observe that this is a popular subject and many men would presumably
desire to enlarge their penis (despite this being in reality of next to
no interest to their heterosexual partners), which makes it (highly) worthwhile to encourage discussion favouring such an enterprise,
particularly where one might be marketing a "
product".
The
main reason I would suggest that stretching the penis is unlikely to be particularly productive, is that the Tunica albuginea (the sheath of the corpora cavernosa) is
not skin - it is decidedly tougher and essentially "designed" not to stretch (just as are ligaments and tendons). I would not call it
impossible, but expect it would require immense determination; rather more than any of the enterprises above. And I perceive a
very real danger that the various methods of "jelqing" to such an extreme extent would cause damage to the erectile mechanism within the corpora cavernosa - need I say more?