I have no shame, and do this with all degrees of sensitivity, from irritation to full allergy and through to exacerbating eczema. I have also no shame in taking close-up photos of afflicted skin (date- and time-stamped) and sharing the joy with makers of stuff I’m taking back.
Alas, different rules for different countries.
However: It’s unethical to do the following, and in any sensible place would be illegal too (is, in some places):
1. sell stuff claiming it’s suitable for sensitive skin when it isn’t;
2. sell stuff that hasn’t been properly tested out on sensitive humans in the first place. I don’ t care if it’s organic, hand-made, and a small family business. There are professional standards, and responsibility to consumers; let alone respect for their rights, we’re just talking obligations and duty of care here.
3. and, indeed, sell stuff that irritates in the first place–luckily some countries have more consumer protection legislation than others; I’m more of a socialist and less of a free-marketeer on this issue, with apologies to any Americans on here who might find these ideas upsetting
4. be a shop and not have any testers, and refuse to open testers (Sephora in Canada, looking at you here), so the only way I can try something is by buying (I’m more of a free-market libertarian on this one…)
5. employ SAs who are incompetent and/or ignorant, not fully trained or untrained, underpaid and uninterested, stupid, ill-informed, with kindergarten-level scientific knowledge, myth-propagating, full of folk wisdom, or some combination of the above… so I can’t trust their advice and guidance (and nor could any sane, rational human with functioning brain)
6. ditto, SAs who pressure potential customers into buying without testing products out properly first: ie. patch-test in several areas, leave to rest to check for reactions over next 2 hours, and allow you adequate samples to test out over a 2-week period to check for lower-grade irritation.
7. same for the two points above, as applied to cr**py so-called customer service.
8. be an online shop and not at least sell cheap sample/tester sizes, and have at least a 2-week return policy.
9. be more interested in making money than anything else: making good products, environmental responsibility, duty of care to other fellow human-beings, etc.
10. do all the above at grossly over-inflated prices that bear little to no relation to ingredient and manufacturing costs and staffing overheads; and employ waste-of-space middle-men along the way; the more so if some of that surplus has been spent on marketing, advertising, sales, and product placement playing on consumer fears, anxieties, and desires; and other unethical manipulative malpractice of that ilk.
Ten Commandments for world businesses and consumer rights?