Morning Phillip.
I took a couple of chairs away to have a play a few weeks before, tried a few high PH chems prochem up was ok craftex champion was better,
i then tried a floor polish stripper and that was excellent. job was booked for the 6th as school was closed for teacher training.
Method used 400ml in to a 6ltr sprayer with hot water sprayed the chairs outside.
Cut down a red hard floor pad with a stanley knife and used that for agitation & a tampico brush wear gloves or the high ph14 splits your skin next day.
rinsed the chairs after with a normal garden hose with a gun on the end.
Be careful using a high pressure jet wash on them as the plastic coating on the steel legs can blow off
chairs placed with back legs touching the wall to drain.
caretaker carried them all out and put them all back bonus
Hope this helps.