The Chida writes that sometimes the Yetzer Horah convicnes us to do a good thing. He has his reasons – maybe he wants us to become baalei gaavah, or maybe he wants you to think youre better than other Jews who dont do whatever it is you are doing, or maybe he wants to distract you from the real issues you should be focusing on, whatever.
The Chidah says the way to tell whether our action are Yetzer tov-driven or Yetzer Horah-driven is to see whether they are consistent with our general spiritual standard of living. If they are not, if a certina hanhagah or chumrah is inconsistent with our general lifestyle, then it is probably the Yetzer Horah’s idea.
Thats my point here. One of the olden-day Roshei Yeshiva in YU, Rav Ueruchem Gorelick ZTL, a Rebbe of Rabbi Hershel Schechter who I know is into this techeiles, used to give a moshol for this:
A guy is at a wedding and everybody is laughing at him. He goes over to one of those guys laughing and asks him why hes laughiong. He sayd “look at you! youre missing your tie!”. He as wearing a facny tuxedo, but an open shirt with no tie.
That night after the wedding he gets undressed, gets into his pajamas and goes to bed, when he hears the doorbell ring. He gets up, goes to his drawer, puts on a black silk tie over his pajamas and answers the door.
At the door was the guy who was laughing at him by the wedding, standing there, laughing at him again.
“Why are you laughing at me now?” he says.
“Because youre wearing a tie” he answers.
“What? You must be crazy, the guy in pajamas says. First you laught at me because I am wearing a tie, and now you laugh at me because I am not wearing a tie. Make up your mind!”
The answer is, if youre wearing a tuzedo, a tie is a goo thing. If youre wearing pajamas, a tie is weird.
Same thing with our nehsoma. Certain actions are nothgin but weird even if they are chumras, becuase they make no sense in context of our lifestyle. Its liek were in pajamas and suddenly we become so frum regarding this one little thing. It shows theres somethgin wrong with the way we look at ourselves and our religiousness. If we had a healthy outlook, wed bother with other things first.
So if someone like Rav Elyashev shakes his head at this techeiles nad says its nothing at all to be concerned about, that theres zero reason to bother with it, your “in case its a good thing” attitude is misplaced. And if you were living a lifestyle like that, it would still be unrealistic, but at least it would be consistent. As it is, I think you should reconsdier the whole idea totally.
Oh, and of course certain doors need two mezuzos – one on each side, to fulfill disagreeing opinions.
(And I didnt even mention chodosh…)
This techieles wasnt even accepted as a real shitah. There are seriosu quesitoins as to whether it is real, before you get to the Arizal. Its really not worth doing.
And you dont need any brachah to wait 72 minutes after shabbos. I think whoever told you think probably means hataras nedorim anyway, nto a brachah. But you dont need any such thing. Theres no minhag in anybodys family to do melachah right after shabbos. Teh majority of Rishonim, inclusing the shulchan aruch and the nosei keilim, hold that shabbos ends 72 minutes after shkiyah. It is a quesiton of sofek chilul shabbos.