How do you do RC exercises?

I'm having stubborn RC issues. Oddly, I didn't recognize that I was having trouble till I returned to the pool after about 9-10 days away on a ski vacation (no injuries incurred on the slopes). I could justify living on Alleve through nats, but now I know I've got to get this under control. I started back in on my RC exercises that I was given a few years ago. I'm sure they're the standard ones we've all been doing. What surprised me was that my wife (a non-swimmer with RC issues of her own) looked at me and said "What are you doing?". And in this case, I think she was right. I was muscling up an 8# weight and doing around 15 reps for each exercise. She said that her therapist insisted that resistance for RC exercises should be low, since the muscles involved are small. As soon as you increase the weight, this logic goes, you start recruiting the bigger scapular stabilizing muscles and do nothing for the RC. She was told women start at 1# (or less), men 3#, but never more than 5#. Each repetition is held for about 2 seconds, and then repeated for up to 30 times. I don't know where I went astray here. I've started doing my RC exercises with my wife's direction. My shoulder still hurts when I swim, but after doing the exercises, it feels, well, different. Maybe more stable. Any thoughts?