Is there a trick to get Hayward cover off wall skimmer?

[kyles974]

Ok, I've tried everything I know?
The cover for the Hayward wall skimmer is hard to open.
I've tried very fine sand paper, silicone o-ring lube (which seem to work well but attracts sand which makes it worse)

Is there a tip or trick to allow this bugger to slide open easier?

 

[one_knight4u]

When I need something lubricated but not to attract dust or sand, i use paste wax. might be worth a try.