my avid elixir 5 levers are squeaking. if i put some finish line chain oil (with teflon)in between the pivots is this likely to damage anything ?

I’d recommend something like a silicone spray (this, which is, believe it or not, more use to MTB maintenance than GT85!!). It’ll leave a dry residue, so no build-up of dusty/greasy stuff that might actually increase wear.