I'm sorry to say but this someone is incorrect. I got my information first hand from the actual embassy and I think they know what they're talking about. 🙃
Most of them allow you to apply without being a citizen or permanent resident. Taiwan being one of them. Japan for example does not allow tourists to apply. You have to be a citizen of Japan or a permanent resident there. In any case you definitely need to check with your local embassy because every country is different. Other countries where it seems to work are Laos Cambodia Malaysia Singapore Indonesia.