1. You can slow the brew process by taking a used K cup and cutting off the top lip and wide flange so that it will fit far enough down inside the My K cup holder so that the brass basket will still fit properly. You will be AMAZED at how this simple and free method will increase brew strength.
2. If that doesn't work well enough for you, try grinding the coffee/tea to a finer grind.
I found out by trial and error that doing BOTH made the brew SO STRONG that I won't have to regrind. Just the addition of the k cup underneath the My K cup basket is enough to dramatically increase brewing strength. Sometimes the simplest solutions are the best one!
Resist the temptation to place huge amounts of coffee/tea into the My K cup basket, after following the method I just outlined. I can use far less than 1/2 a basket-full of tea to get a strong brew.