'Muff' powerful words there but sadly true
All Co's as you mentioned count on the fact that solidarity is dead. The notion of working to rule so to speak is terrific but as others have said to be effective it has to be done by ALL.
I'm not sure of what's written in the current EBA at REX but most Co's tend to write in that your expected to work a fair & reasonable O/T when asked, nature of the job, The word 'reasonable' is questionable & is open to abuse I guess.
Yr worth more guys/gals that's obvious if what's been said in here over the years is anything to go by but getting that point across to the management will take a huge effort by ALL.
Good luck
CW