Wrapping Polytetrafluoroethylene around a slackened compression joint threads WILL NOT WORK. End of. No iff's, butt's or maybe's. You will never get it around the olive without draining down as I'm sure your well aware of. Not unless you wish to canoe in and out of the room that has the leaky joint.
You can try to tighten the nut to compress the olive further onto the pipe. In a lot of circumstances, this will work. In some, it wont. If you deform the olive or pipe, your going to make a bad sitaution worse.
In your last post you stated
I tried to slacken the nut but got more water than i bargained for
What on earth were you expecting; a dribble? Its a 'live' joint with a fair bit of pressure behind it - even on an OV system.
Leak sealer on this simple repair is a blatant bodge, so either do it properly yourself (drain it down and remake all the weeping joints) or get a recommended plumber who will do it for you. I cant speak for all the other plumbers who have commented, but it seems you have had every bit of advice available now.
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