Dunno how sensible it is but last time my LBS looked at my bike he told me to start using GT85 and nothing else
starting with a clean degreased chain then just using that on chain and gears
he said the PTFE from the spray is all it needs
any opinions??
EDIT - oh - and he said to be careful to avoid the disc brakes with the spray - he said he has had a few back that need the disc cleaning and sometimes pads replacing!!