I have no idea how to tell if cukes are gonna be bitter or not, but I grew up doing something similar to what blues does.

Peel and slice cukes thinly into a bowl, add lots of salt; cover and set in friggie overnight. Drain and rinse well, add favorite salad dressing and enjoy! When I lived in Germany, the Germans would make a dressing with sour cream and fresh dill. Being French, I always have mine with a homemade garlic vinaigrette and I don't think I've ever had a "bitter" cuke...