from my experience and reading, the grubs prefer acidic conditions...which azaleas also enjoy
you can tell whether you have acidic soil by either doing a ph test or if you observe thatch building up in lawn...as acidic conditions slow down or even prevent biological breakdown of matter. if you do have a generally acidic soil, and not too many azaleas/camellias/etc planted around the place, then a good addition of dolomite all over the garden soil will add the needed calcium and make the conditions much less to the grubs liking. once their numbers are reduced in the general garden, there won't be many to infect your pots.
as a temporary measure for the pots: submerge in water for a few hours...so the curl grubs drown.