if you are working for an airline in a position where you have to complete the wet drill, you really should know that airlines are in position to extend the minimum legal requirements with their own requirements and SOPs.
There is no requirement for a person to know how to swim to issue a licence and this is as far as the licencing authorities will take it. You can then go and look for a job with operators that fly inland (bush flying?) and will not require you to do the wet drill..
if the operator deems that it is necessary for the crew to know how to swim, then wet drill it shall be and no CAA in the world can object to that .. no legal framework in the world can dictate what additional skills employer can or cannot seek for