How dirty is the tank? Or is it just to decontaminate it before setting up a new tank?
They will just mean normal white vinegar, I have seen it recommend for cleaning lots of stuff over the years.
The approved scrubbing pads is a slight gimmick imo. The scrubbing pads you get from a pet shop are slightly less abrasive and gritty so less likely to leave bits in your tank after use. However, I have only ever used 10 for a quid Poundland sponge scourers and they have been fine. You really dont need much force when cleaning with them. But be careful as it doesn't take a lot to scratch the glass.
Buckets - Must have! For water changes, cleaning, temporary fish storage etc. I have a couple of 99p buckets from B&M that do the job. If you have a big tank thank bigger buckets are easier.
I have always found good soak in warm soapy water then rinse will do the trick for cleaning a tank ( I base that on having cleaned 3
). All your ornaments, wood, fake plants and filter attachments can get a quick boil in water if you really want to decontaminate them.
Any other fishy related questions just ask