Yes.
In my company and I am sure many others, the cabin crew are tested on random procedures by the senior cabin crew member. If the individual cannot satisy the questioner they are replaced for that flight.
I am sure no system is perfect, but the requirement to be regularly checked places an additional imperative for the indivudal to keep up to speed on procedures. This coupled with recurrent training and the ability of good CRM principles to balance any weakness is probably as much as can be reasonably expected.