It was available in 500 or 250ml in date stamped plastic bottles from the chemist. Tackle shops weren't quite so careful.
Liver powder and flavour does mix quite well with a sweet cajouser.
One thing I will say with hi-attract wafters and pop-ups is I've done best when they are fished on their own with few, if any freebies around them.
Banoffee is a decent flavour at a low level with a food bait, but I've not done well with it in hi-attract baits.
I've played with various hi-attract baits, flavours and the like.
Some good ones are garlic and spice, pineapple (and N-butyric), green zing, squid and octopus, Tutti-Frutti and black pepper.
Other flavours didn't work for me, and believe me I tried loads.