There was certainly a period (Mid 70's-Early 80's) when tape manufacturers, experimented with new backings and coatings. I'm thinking in particular of BASF LR56...(It had a yellowish backing with BASF printed on it IIRC).
It was quickly abandoned by the BBC as unfit for use....Mainly by the maintenance team who had to clean the shed oxide from the capstans and the pinch rollers.
So, If anyone has BASF tapes from that era. Treat them with extreme care, particularly if the recordings are of value, and seek the advice of professional restorers....Don't play them at home...!!
Even with "baking"..quite a lengthy process I believe, You might only get one chance to retrieve the audio. If you think about it, the tape passes the playback head with minimal friction, and immediately encounters the capstan/pinch wheel. That is where the damage is done. Like a previous poster has said, I've watched oxide shedding leaving an almost completely clear film on the take-up side.
So, my advice would be.
1. Check a small portion of the tape with nothing of significance on it first to see what happens.
2. If you really have to play the tape, make sure that your record equipment, (Digits, Hard Drives whatever) is running...!
It might be the last time you get any audio out..
Remember, All technology only lasts as long as it's been in existence. Who knows about the future?
So, paradoxically, 78's are the best medium for audio storage!!! (or maybe cylinders!)