So gave the bike complete clean with muc off products, done in half an hour. Sprayed down drivetrain with MO 94 after cleaning, lubricated chain.
Never felt the drivetrain move so smoothly, looks like a clean has been needed for a while. Has made a big difference.
Muc off products seem to work well, I got them because they were on sale and claim to be environmentally friendly. Checked with Muc off if I needed their drivetrain cleaner, or if the Nano tech would work ok for cassette. He said Nano tech should be fine, their drivetrain cleaner goes deeper.
Had a Specialized hybrid way back in the 90's, didn't pay much attention to maintenance to the detriment of the bike. So have learned a lesson from that.
Half an hour once or twice per week, well worth it.
Going to invest in a stand!