According to R Nissan Kaplan’s shiur on this inyan, there are actually many rabbbanim who do where tcheiles including
Rav Chaim Pinchas Scheinberg- ( he called his son to find out and was told that some of his tzitzis are tcheiles)
Rav Zalman Nechemiah Goldberg
And Rav Yaakov Kamenetzky told a well known rav ( who shall remain anonymous) that if he learns it up and thinks it is tcheiles than he should where it btzinah.
Rav Chaim Kanievsky said it is like dam chamor and it is worthless but can’t hurt.
Rav Elyashiv in a mefursam Teshuvah (kovetz teshuvas chelek 1 siman 2) says although there is many proofs to this [murux] tcheiles we could still be choshed that in later doros it will get disprooved, like the radzhiner.
?? ?? R nissan kaplans shiur ( can be found online in halachah 5770-55-tzitzis-2-techeles.mp3 (31.02 megs) )
I personally where this tcheiles and so does my father and brother. I am not mizrachi . But the reason it is popular amongst the mizrachi crowd, is probably because the murux was decided as the chilazon over 70 years ago by the cheif rabbi (who then was actually a rabbi in Ireland) Reb Yitzchak Isaac Halevi Herzog ZT”L. [ who was held of in the chareidi circles] He had many proofs but could not figure out why it was not blue but rather purple. Than 20 years ago it was discovered that if you leave it in the sun for a half hour it turns blue.