I need to keep the glucose levels up on my BC x and the vet has suggested feeding twice a day and maybe even a third smaller meal at lunchtime to keep them up.

He is currently fed CSJ CP24 in the evening and has a kong filled with naturesmenu in the morning.

Now question is, will he get the glucose easier from wet or dry food.  I seem to remember someone saying that a dog will get everything it needs from wet food quicker than dry but maybe that is just an old wives tale.....

I think you need your vet to explain a bit more.  What does he mean by glucose?

If your dog is hypoglycaemic then it is important for the dog to eat little and often to maintain blood sugar levels; it matters not whether the food is wet or dry but you should be looking at the nutritional content.